I'm 5'9 (175cn), 130 pounds (59kg), early 20's. Very low body fat, visible abs and muscle. I'm genetically very skinny, I just can't eat much food. Currently I'm doing a lot of martial arts so it's not possible for me to gain weight but soon moving for college after covid and I'll do less martial arts and more gym.

For a year and a half that I've been lifting I focuses on compound lifts, almost 0 cardio and I wasn't able to gain more than one pound. I added a fourth meal to each day, I've gotten stronger, lifted a lot more than the beginning, a bit more visible muscle, but overall stayed the same size and gained some knee problems from all the deadlifts and squats (although technique was good so I have no idea, my legs are like sticks so maybe although I gained muscle my body wasn't ready).

When I get back to lifting, what should I do differently? Are there good posts / programs / communities for me to follow? Thanks.