Welcome to the Guild, Cleolith! I always recommend new people, whether new to RP or just new to here, check out the guide here, it fills you in on how things are done around these parts. If you have any questions there is a thread here specifically for them, also feel free to PM me if you require any assistance with anything.
18+ content isn't allowed, this is a PG-13 site anything above that level needs to be taken to PM. As for where to RP, the Guide will help you out the best. But things here are divided by level. If you look in the middle of the forum under this intro section you will fine our RP section. With Free, Casual, Advanced, Arena and 1x1. Each has a sub forum for OOC and Interest checks. You will want to look in the interest checks for New RP's looking for players. Happy RPing!