Hey Worren! Welcome back!
As a starting point I’d 100% recommend the Wyrmrest Community Project discord! Such a great hub of RP discussions and ideas on both factions. See the link below.
Otherwise check out the forums and see what you’re interested in! I assume as you’re maining a Blood Elf you might like Sin’dorei RP? It could be worth looking into Blood Elf guilds or discords!
If you like random RP the main hub for Horde is the Valley of Honor in Orgrimmar. You’ll find people there at any time in the day. Sometimes you’ll see something happen in Silvermoon but it’s rarer now.