Welcome to Argent Dawn!
A lot of guilds are very excited to teach new RPers so I wouldn’t worry about that.
Not at all. I think you should start with a simple concept and fill out the backstory of your character as you go. Checking up on a bit of lore around the race/class you choose is also helpful.
A lot of RPers do normal content as well so yes, it’s the same.
I think some very minimal knowledge about the lore would be good, especially lore that is relevant to your character’s backgound, but it’s more then ok to not know most of it and find out IC.
Stay away from Goldshire and the Bazzar in Silvermoon as those places are filled with harmful people and predators.
I would say a few addons are very helpful. TotalRP3, CrossRP and Listener are what comes to my mind, but you can learn more about them and experiment with them at your own pace.
Also, I see you’ve posted on a Void Elf. I don’t know if that’s the character you want to RP on (assuming it is) but here’s a nice guild that might fit Umbral Reliquary 🔮 - Void RP
Enjoy!