Welcome to the world of RP!
There’s lots of interesting guilds on both Horde and Alliance but seeing as you want to dip your toes in the Dwarven side of things, here’s some Alliance and Neutral guilds in no particular order:
The Seventh Legion
All Alliance races
Military RP focusing on the Elite aspect
Contact: Théón
Info: [A-RP] The Seventh Legion - Sixth Cohort
The Three Hammers
Dwarven
Military RP with a focus on guarding Khaz Modan
Contact: Gemir
Info: [Dwarf-RP] The Three Hammers
Black Sun Collective
All Alliance
Criminal/Shady RP
Contact: Tessalyn
Info: [A/N RP] The Black Sun Collective (Disbanded)
The Fallen Leaf
Neutral
Mercenary/para-military RP
Contact: Shuang
Info: [Pandaren-RP] 🍂 The Fallen Leaf: Hiatus
The Knights Gryphon
Alliance
Military RP, focusing on aeriel and chivalric themes
Contact: Ashéton
Info: [A-RP] The Knights Gryphon - Rally the Knights Errant! 🦅
Clan Stormheart
Dwarven
Clan-oriented RP
Contact: Thrôrgar
Info: [A-RP] The Knights Gryphon - Rally the Knights Errant! 🦅
The Lionheart
All Alliance
Adventure RP with a focus on heroic characters
Contact: Lotheridan
Info: [A-RP] The <Lionheart>
There’s a bunch of other excellent guilds that I’ve not linked, but I recommend just diving in and reading about them all here and on Argent Archives.