Hey Jackoneill. There aren’t a lot of Merc corps in Eve. The only active one I know about is Noir. (https://evewho.com/corporation/1239884823) They are a good group of people I know from way back in the 2011-2012 Syndicate days.
If you want to try something else, I think you should join Mouth Trumpet Cavalry [MCAV]. We are a C5 WH small gang PvP group. I have been in a lot of groups in my almost 10 year in Eve, I can tell you that MCAV is the best one I have been in. We function a bit differently than most, but I can tell you that the differences make MCAV the place to be. WH space is the best space in Eve for PvP and PvE. Take a look: C5 MCAV is Recruiting all Skill levels or join “mcav-public” in game. Good luck either way!