First and foremost welcome!
Also,
to answer your question, being "bad" at Terraria is of little consequence, there's
way too many tools you can use to make up for lack of skill; because I have such
bad aim and coordination, I use Minions and a LOT of homing/ scatter Ammunition [when playing Ranger Class]. As long as Enemies and Bosses are dying, you're doing what needs to be done, I wouldn't get too caught up in "who's better than who" in this game, a simple Class switch could turn the tables
almost immediately!
Lastly, the Sniper Rifle weapon has a high skill floor and ceiling, if you wanna get good with it, you'll need to practice... a LOT. However, if you want
somewhat similar power at the cost of damage,
but more accuracy, try using
Chlorophyte Bullets, or even Crystal Bullets [anything that has a
volley or some form of homing ability].