HELL YES I DO! So for starters, backstory. You can do without it if you want, nobody will care and it's moreso just on whether you want a deep past or whatever that'll influence their actions. I personally have a character without a real deep backstory and I just play him for fun. IF YOU DO ADD BACKSTORY, MAKE IT OVER THE TOP AND UNREALISTIC. That's the thing with SRP culture, every backstory is over the top, or unrealistic, or both. So have some fun with it! I had a character who had a backstory that would fit better into DnD than it would SRP, but I just changed a few names and... My rogue Wartov turned into my Korean named Mark.
NEXT IS APPEARENCE! If you want to be taken seriously, get a good skin. I'm not trying to be rude, but people subconsciously judge you based on your skin. To test the prejudice, I went on a new character who had a bad skin and a green tag (Normally meaning a newer player) and nearly nobody spoke to me except for other green tagged individuals. What I'm TRYING to say, is get a good skin. Don't need to be tailored, just look on NameMC, they got some pretty good ones on there. And next is PERSONALITY!
Make them likeable, don't be that guy who's a jerk to everyone then says "That's just how my character is". That said, you don't need to make them necessarily NICE, either. I have a rude character, in fact the same one I did the bad skin test on, and people like him. It's sort of hard to explain, but just imagine you're somebody else looking in, would they see a funny but rude guy, or a rude bastard? You also need to make sure that they have an ACTUAL personality, strengths and weakness.
Now we have HOW TO ROLEPLAY PROPERLY. This is a serious section. You can disregard everything else, but this section here is important, and should be taken into consideration to ensure you and the people around you have fun. If you make your character inclined to gang violence, roleplay it right. Know the combat rules, and know how fighting works IRL so you don't do something like *Mrdrs u in 1 shot*. Next part here is pretty much the same thing, READ THE DAMN RULES. So many new players (Myself included when I first joined) don't read the rules. You NEED to read the rules to have a proper understanding of how to play, otherwise you and everyone around you will just be frustrated and won't have fun. Another important one is to remember that YOU need to interact, don't just sit in one place and expect people to approach you. I know it can be awkward but you just gotta try. Strike a conversation over something dumb, like hand them an apple or somethin'.
Definitely a second on this one.
Speaking to the "unrealistic backstory" thing, honestly I'm glad this is a thing that pretty much everyone agrees upon doing for whatever reason in srp. I mostly say this because I was thinking about the backstory I whipped up for one of my characters, which on the surface looks perfectly feasible but upon further inspection doesnt really make sense. My guy's entire thing right now is that he's some poor russian dude stuck in japan, and I have no idea how he managed to enroll in the school or any of that because he was def too stupid to bring his birth certificate or any records like that when he shortsightedly ran away from home...
But in all seriousness, srp is pretty wack and literally nobody cares about it making sense anymore. I mean, we've got highschoolers walking around with multiple prosthetic limbs and gang tattoos, and no one gives a second though to it.
Also, for as long as youre a 'greenie' (the term used by more seasoned players to describe newer players in grade 7-9; not always used affectionately :p), youll want to try to put more effort into being approachable. Most of the time people do tend to avoid newer players, which is a sad truth abt srp, but a lot of times other 'younger' players will form groups so if you can get into one of those you can grade up together and you wont be alone :D. If youre gonna try to talk to people, though, I would recommend 9th graders since they are closer to getting out of 'greenie' level. If you can hang out with a red-tagged player as a greenie, you basically get a free pass of talking to other experienced players since they can see that you atleast somewhat know what youre doing. I know this from experience because I have a few irl friends who joined the game while I was 'older' (red tag), and them being greenies for a while didnt stop them from having fun rp experiences because they were able to more quickly mesh into the community just due to them having a leg up from me and my other red-tagged friend being there.
As for starting conversation, I like to do this in a way that fits my character - for example, my current main is generally a blunt and inattentive guy, so sometimes if a group catches my attention, ill go '/me stares at them <doing x>' and literally narrate myself watching them do whatever. I like being generally comedic with it when Im being weird or rude, since that helps keep you from looking like a creep (if you just put '/me stares' its kinda just weird). Something that I tend to do alot also, which most people dont but I find it fun, is to tack on a :) or other lil text emote onto completely unrelated actions, like '/me rolls his eyes and glares at <person> :)'. The smiley face was completely unnecessary and doesnt fit with the action, but it kinda just serves as a reminder that Im not *actually* a jerk and to take this stuff with a grain of salt - its a rp, after all. Plus I think it makes my 'rude' character generally more approachable.
Another thing I would recommend is to BE EXPRESSIVE!!! :) Use that /me or /action and have fun with it. I have to rely on this a lot to get my point across, especially because one of my main oc's traits is that he struggles with speaking Japanese (oh yeah btw even though youre typing in english your character is canonically speaking japanese because of the setting of srp; ik, confusing right, :p) so I cant just *say* everything. And by the way, you can totally do stuff like that- if you want your character to have a struggle, give it to them! My character isnt confident in japanese, so I frequently rp out him getting confused easily or talking with generally simple structure (like using present tense verbs for literally everything and leaving out connector words alot, mostly before nouns like not saying 'the' or 'a' or just leaving them singular when they should be plural, stuff like that.) and frequently just having him talk in russian (though this tends to annoy the teachers, so I usually have to be careful when doing so in some situations.). I would definitely recommend giving your character quirks or flaws, since it generally makes you more interesting to others and makes your character seem more realistic and 'alive'.
But importantly, learn the commands to do stuff and put effort into using them - like /w for whisper, /me for action, /LOOC FOR TALKING OUT OF CHARACTER!! Seriously, not much annoys a seasoned player more than people talking oocly in in-character chat. For whatever reason, most people just hate this. So I would recommend using /looc because itll automatically make you seem that much cooler to other srp people.
Ill stop rambling now, if you read all of my spiel, thanks and congrats. :)
I hope some of this will actually be useful to atleast someone, :p