Welcome to the RP community! I don’t think you should have any trouble with most guilds, especially if you just let them know that you’re learning how to roleplay. I’ve had a lot of good experiences with folks on this server since I’ve transferred here!
I can’t think of any Sylvanas loyalist guilds off of the top of my head, (I think I saw a few some months back, but I’m not sure how many active ones are still out there.) but if you’re up for trying out other guild themes while having the loyalist thing be a secondary aspect of your character’s story exploration, here is a directory of some of the active Horde guilds: Horde Guild Directory Thread
I also highly recommend the following addons:
Total Roleplay 3 (This is one of the most-used addons for roleplay. It allows roleplayers to make custom profiles for their characters, and tends to be an easy indicator of who roleplays. Not everyone who roleplays has this addon or one like it, but a large number do. There is also a separate add-on called TRP Extended (you still have to download TRP 3 separately - it doesn’t come WITH TRP 3 included) that adds additional features.)
Cross RP (Allows you to see the profiles of people of the opposite faction, and lets you know when the item Elixir of Tongues is about to expire. Elixir of Tongues is a potion sold in the sewers in Legion Dalaran by a goblin that allows you to speak to and understand players on the opposite faction when they speak in /say, /yell, and /emote.)
Listener (At events or in areas where a lot of people are roleplaying at once, your chat box can get filled up easily. This addon helps you distinguish who is talking to you / people you’re trying to see the responses of / brings up a certain subject /etc. It highlights words of interest and you can add custom words of interest (by default, it highlights your character’s name or parts of their full name) and makes an instant message-like noise when it detects a word of interest, or when the person you have targeted says something or does an emote.)
I hope that any of this has helped! I also really recommend keeping an eye on the forums for public events. A lot of people host open roleplay events that anyone can attend. Some are faction-specific, but most are neutral. It’s a great way of getting to meet new people, and practice getting a better idea of who your character is.
What’s nice about events is that you can often meet potential guilds you’d want your character to join, and there’s no pressure or commitment to join. You might just spend an afternoon roleplaying with a group from a particular guild and think to yourself, “You know, these people really reflect a lifestyle that I would want my character to live! I should ask about joining.”
Like with anything else, roleplay just takes practice and trial and error. It’s also very normal for you to start out with one idea of who your character is, and to wind up with them being totally different as you start roleplaying with them regularly. That happens to me all the time!
Ultimately, just go with what feels “right” for what you enjoy for your character and their story, and don’t give up if at first the learning curve seems a little challenging! Yeah, there’s a lot of things to be learned: Character building, lore, etc., but the majority of people don’t expect perfection.
Honestly, roleplay anxiety reminds me a lot of “new job anxiety”. People tend to worry a lot about performance, their skill level/capacity, and how well they’ll be able to do all the tasks, but really the most important part of doing well is just showing up consistently, trying your best, and having a positive attitude!
As long as you keep putting your character out there and initiating interactions regularly with other folks, you’ll do just fine!