Hi Loraven, welcome back!
If you are familiar with Discord, I recommend checking out the Wyrmrest Community Project discord server as they have a Guild Directory you could browse through: Wyrmrest Community Project - Wyrmrest Accord - World of Warcraft Forums (blizzard.com)
The directory there includes summaries about what each guild is all about, so you can peek around until something catches your attention.
For Sin’dorei focused RP, you might be interested in the Sunfury Batallion: [H-RP-PvP] is recruiting for Shadowlands! - Wyrmrest Accord - World of Warcraft Forums (blizzard.com)
Or the Sunreavers: [The Sunreavers] Shoutout to Gavinrad and his latest video on WrA! - Wyrmrest Accord - World of Warcraft Forums (blizzard.com)
May I also recommend my own guild, the Violet Vanguard! We’re a cross-faction band of heroes focused on world RP, multiple DMs and we try to hit a variety of themes and activities week-to-week: [H/A RP-PVE] Violet Vanguard Recruiting for Dragonflight! - Wyrmrest Accord - World of Warcraft Forums (blizzard.com)
A good questions to ask yourself while you’re browsing is what kind of RP are you hoping to engage with? Adventures out in the world? Long-form campaigns with a group of players? Military themes? A little bit of everything?
Also consider your time zone and find a guild that’s most active in your hours of play. 