The first place I can think of to look would be the Horde Guild Directory.
And you’ve got a lot of options. Off the top of my head, there’s Southfury Watch, Sons of Varok, Scarred Blade Clan, Gorantha Warband (spelling?). All of them are moderate sized guilds where I’m sure you’ll find people eager to help.
It can be a bit harder to find because for obvious reasons, these types of RP’ers don’t spend much time in the city being social or hosting/attending large social gatherings. The few events I know of that would be best are the Spring Kosh’harg coming up in a few months, and the newly founded fighting pit event. Not sure when the next one is, but feel free to check out the thread and join the Discord.