Welcome to RPG Corvid, we're glad to have you here.
As for etiquette, that's not something I generally see asked about. So forgive me if I'm a bit behind the times on things, I'm from an older generation of players (yahoo/MSN).
Generally, my own personal rule of thumb is if you see a RP you're interested in, instead of just jumping in and posting or submitting a character, PM the RP owner or make a comment in their OOC forum attached to it. Some GM's of the RPs that aren't the Multiverse can be really picky about things being done a certain way.
Also here are a few links that can help you get adjusted to the site:
Roleplayer's Wanted This is where you'll find established Universes & GMs looking for writers / players.
Interest Checks This forum is generally Brainstorming / Pre-RP planning, also you can find GMs seeking writers / players before they start a Universe.
Our Chat Log in with your RPG credentials in all lower case & explore.
The Multiverse The front page of arugably our largest RP here on the site, here you'll find a universe full of colliding time lines, factions, and genres. If you want to jump in, spawn a character in
"Genesis" and guide them in character then you will need to go
here. The Writer's Lounge Here you can reinvigorate all aspects of creative writing & encourage others writers to indulge in their interests. Our
poetry sub forum can be found here as well.
The Artist's Cafe Here you can also reinvigorate all aspects of art, both traditional and digital, as well as ask about commissions or collaborations. Also here you'll find our
music sub forum. Medals and Achievements Show off all the medals you can earn by being a member of RPG's community, which come with INK rewards. How many can you collect?
INK Ink is a writer's currency that you can get by earning medals and participating in the RPG Community. Ink allows you to do things like buy locations and tip posts just to name a few things. Follow the link and explore the site to learn more!