I think that RP is a fairly social act, you need to be capable of being social in order to do well, it also doesn't hurt to be able to handle things like rejection and self-reflection is a pretty useful tool for improving as well. I'll give a few pointers.
1. When you make a character make sure that they have a reason to exist. A lot of people actually try to sell themselves as "Just another X". This is why tropes like Headphones Guy exist. Its a sign that someone didn't even thing of WHY their character exists they just made a run of the mill bog standard "NPC" to fuck people on the interwebs. Give people a reason to care about you, give your character a goal, a personality, an attitude. No matter WHAT you make you will get people coming to you so long as it has a reason to exist and a personality to back that up. I've seen everything from LITERAL skull testicles to inter-dimensional blobs of sentient fat get play. Whats important is that you like what you're playing and people can see you took the time to create something worth playing with.
2. Learn to compromise. This can mean a lot of different things. For one, RP is a hobby and sometimes people won't be available as frequently as you'd like. Don't flip your lid on them and accept that people might have things to do from outside of the RP. Don't be a stick in the mud and learn to work TOGETHER with your partner to craft a scene. Only retards like godmodding doms who do nothing but pull the scene around on their own, and no one like limp subs who will just echo what their partner does. You need to be willing to sometimes bend on somethings you want, this also applies to talking about scene specifics before you start (if you do that). If you are too locked into a single idea chances are it'll be harder to find partners and at worst, when you do it, you might find it not all you wanted it to be.
3. Be Reserved. Don't be clingy or become emotionally attached to people you RP with based on RP alone. If you DO end up getting more personal then I don't see why this can't happy, BUT it CAN'T be based on your character interactions. For some people it can be hard to separate these things, but at the end of the day RP is just a hobby and should be treated as such. You can meet friends through hobbies, you make relationships with friends from hobbies, but you should never led the facade get to you about someone's character. That being said, falling in love with someone's character, but knowing it's in a fictional context is fine so long as you keep the two separate.
4. Don't use RP as a means to stroke your ego. You can use it to feel good about yourself, but don't do this. Ego driven players are not worth putting any time into. Not I don't mean overly dominant characters, some people can maintain the facade of an Ego driven character for the sake of RP, but actually be quite likable behind the screen. There are people who even when not in character tho, will talk about all of their "fuckpigs" and how great they are, how many words they write, how many art pieces they own, stuff like that. These are normally just signs that that person lives a shitty life and gain some sort of self value through RP. They tend to be the MOST clingy and volatile players and although a lot of the time they will try to say that they "understand" where they are they don't. These are what you need to look out for, they're extremely petty and not worth your time. Don't fall into the same trapping and become another dime-a-dozen "bow down and worship your new god" (but actually believe it) types.
5. Keep things fun. There isn't a set way to RP. You can do it with one character, with many, you can think up entirely new ways to do things. Never stop trying to change things up and find new ways of having things remain fresh and fun! You can burn out from RP just like with any hobby, so to prevent that you need a steady stream of new stuff. Always keep your head up and never get things get you down, or at least try to minimize or prevent them.