For general RP networking and events awareness, in Silvermoon and elsewhere, the WCP discord linked above is an excellent place.
For Quel’Thalas-specific RP, the Ashen Court discord has a forum thread here. Getting day-to-day walkup going is an ongoing challenge, but we host both twice-a-month and yearly events and have a channel in which you can let people know when you’re looking for RP if you’re so inclined.