Depends. If its both; try to adapt. Find one or maybe two different agents (three is good too) and just figure out how they are played. Personally for me, I play different agents, (skye, kayo, viper, raze) but I just find agents that either have similar playing styles and adapt the differences. When you play omen, put your mindset in ratting and playing for your team, reyna, play for selfishness and picks, and chamber, play for aim and corners.
Aimwise, you just want to practice, Find someone in a similar elo, and practice with them if you have to. I find that it's easier to tap heads if you have lower gun sound, so I prefer skins, but you can try aim training apps, deathmatches, range, or even just some unrateds. That's all I have to say on the matter.. Ig.