Hey there and welcome to WrA.
RP-PvP and WPvP is quite stale here. This is due to a combination of reasons, the two most important being a) game story and b) time. The unpopularity of BfA’s game mechanics coupled with the story has driven motivation to do either RP-PvP or WPvP into the dust. There isn’t much incentive to do it, even now. There’s not a whole lot of honor points to farm or tangible reward that encourages folks to do it. Only one side gets that ability, thus turning war mode into the trashcan that it is now. It is especially important for the shard the WrA keeps getting thrown into.
RP-PvP is niche and right now pretty impossible to do because of the aforementioned game story. Most campaigns would just be considered all-out-war instead of skirmishes.
I have seen a few PvP-centric guilds but I don’t think they focus on WPvP either.
Here is a link to the Horde Guild directory, and I hope you find something that fits.