You can always try shooting range to work on your skill, like I have done many times
Or you can always look for advice on YT.
For me, who always took role as Controller (either Viper or Brimstone) because my aiming skill is so bad, I always try and learn which section on every map is dangerous, every choke point, every ambush point, and every safe route, so i can maximize my teammates's skill and minimize danger by putting my utilities on good points.
Finally, as Sova said to us all:
"If you're not a good shot today, don't worry. There are other ways to be useful."