I think many can understand that pretty well. I still have some struggles with simply going to people and starting a conversation even if I know them already ic. My advice is put both in your ooc Information, that you are new and that you are shy. At least to me personally that makes me want to walk up to you already and in time it will get easier for you too, it’s just the first step that is the hardest. Also I must say that usually Orgrimmar isn’t the greatest place for walkup rp and as much as it hurts my probably orcish heart but if it’s what interests you, you will find more Joy in Stormwind.
Regarding the Guilds, I can only say even if it’s not declared casual we are all here for fun. So even if there is an event every day doesn’t mean you have to come to all of them. I can only speak for our Caravan here but we have the general rule of thumb that you should rp with us (event or not) around two times a week, just so we know you are still active and haven’t moved on.
On that note I can link you two guilds that we interacted with in the past and that could fit you quite well.
One is the Eternal Sisterhood which is totally not a cult and despite the name they take male characters too, just not as priests. If you want Suramar rp there isn’t a better place.
The other are the Highblood Myrmidons. They are more about the lands of Quel’Thalas than Suramar but they have Nightborn among their ranks and are quite the good place for Elf rp in general.