Welcome to MG and the world of roleplay! You already have what I consider the most important addon (there are few others also that are neat but you really got #1 imo and it’s a good place to start) and some ideas for your character. Sounds like you are well on your way. As far as where to find a guild or community, there’s another thread with the same inquiry here:
I posted a couple of discord links to servers that have guild recruitment events. You can also ask for suggestions/advice in there and people can point you to some guilds/communities.
Forum link to Grand Alliance Recruitment Fair:
Forum Link to SW Job Fair (not only for Stormwind guilds, just held in Stormwind)