hello there distinguished individual! i noticed that you hadnt got a reply on your question so i thought i'd pop in here real quick with an answer incase you still needed it :)
So you do not need to make your own skin if you dont want to! Skindex skins are fine, though you'll want to find one that both looks nice and isn't like one of the most popular ones or you'll probably see someone walking around with the same skin lol. happened to me a long time ago, though i had heavily edited the skin off namemc so it didnt look exactly the same.
If you want to eventually upgrade to a more srp-styled skin, you can commission them from tailors (though you have to pay) or make one yourself - there's a helpful guide for beginners you can look at
here. :)
On starting rps, uhhh for that one you might have to just drop kick your fear, anxiety, and social awkwardness into the sun and just go up to people and say something. Most people are nice (keyword 'most') and will be happy to befriend you if you act cordially towards them! And besides, the worst that can happen is that a person declines or gets rude, and then you just avoid them and get on with life.
Or you can be like me and just stand in the corner somewhere watching people and just hoping someone will walk up and interact with my character and them proceed to shove them off because I main a really antisocial and standoffish character :'D (lol)
have fun, and good luck! :)
kj out B)