This is some general advice. If you like what I have to say and have more role-play specific questions, feel free to ask. I do like to talk about role-playing as if I know what I'm talking about. lol
Write what you want to write and with who you want to write. If you feel like you are being nudged to write something you aren't passionate about, then put the stop to that nudging right away. Nothing worse than finding out you aren't into a role-play, because a sour note is ruining the tune. You don't have to compromise on anything you aren't thrilled about. If you aren't clicking with your partner, don't be shy about putting an end to the role-play. It's always best to be respectful and affable about these things, but you don't have to tolerate anything you aren't jazzed about.
Don't be bothered by someone ghosting you. You are going to get ghosted, which is just the term for when someone suddenly cuts off communication during planning or role-play. It's something that happens to everyone, so don't take it personally. The best writers and role-players here will get ditched, usually for no good reason, so don't feel like it's a poor reflection on you. You also shouldn't feel pressured into a confrontation with someone if you'd rather ghost them for whatever reason-- it's about you dictating the terms of your engagements with others in a way that makes
YOU comfortable.
The more specific and unusual your wants, the harder it will be to find potential partners. Don't be discouraged if it takes you some time to find what you want, because sometimes that's just the way it is. This is even true if you're advertising the most popular of things. If the rare stuff is hard to find because nobody is doing it, you can also reason that the popular stuff is oversaturated and people might be tired of it. Finding a partner can be a complete gamble, so be patient if things are taking a while.
The less you care about who is on the other side of the screen, the more potential partners you'll have.
Your presentation matters to some extent and will attract or turn away some people. Keep in mind how you want others to perceive you. If you are rather fancy, wordy, and involved looking, then you are likely to get some higher quality writers who take role-playing more seriously. This might also intimidate some writers. On the other hand, if you put zero effort in presenting yourself, then some more experienced writers might "write" you off as being less skilled. Likewise, it might attract some writers that aren't looking for literary monsters. There are also plenty of people that won't care either way.
If you want a good avatar and signature set made for you, or other graphics and images, check out
Blue Moon Artist Showcase. At the time of me typing this message, I think
@Retrojapan is the only member taking requests; she's pretty good. You can get some nice work from her.
Just focus on having fun. Don't get caught up in word counts or other nonsense. Just write what is fun for you and treat this as a relaxing hobby and not a job. This isn't a job. You are not obligated to role-play while burdened with the pushy expectations of others.