It doesn't matter if you are zeroing or not , NEVER jerk the trigger, always squeeze, it should be comfortably and safely light, and break cleanly, if not have it looked at.
Zero at a distance your land, quarry and ammo require! With .22LR subs most will zero around 50-60 yards. High velocity .22LR will be lucky to group at 40yards but is commonly used to -100yards (with shotgun patterns)!