Most all guns (rifle/pistols) have the bore tilted up a bit in relation to the sights. (google firearms ballistics...or external ballistics). Your line of sight (LOS) is straight...and let's assume level/horizontal.
The Bore Line is not level/horizontal...but rather slanted so the muzzle is a bit higher than the chamber end.
So when you point the sights at a target...your LOS is dead straight from your eye, through the rear sight, past the front sight and to the spot on the target.
The bore line, which sits about ~1cm lower than your pistol sights (depends on what pistol you have) is, at that moment, not really pointed at the same spot (i.e. if you drew a laser line down the bore it'd be pointed higher that your Point of Aim (POA).
Now the projectile comes out and immediately starts to drop...gravity...so it crosses your LOS pretty close to you then falls and crosses your LOS again. This is your "zero'd" range. Could be 30', could be 1000yrds. Depends on what you're shooting.
However...for airsoft guns where backspin is applied that creates lift on the BB, the BB doesn't follow a traditional ballistic path. It's more straight out and then drops. There might be some ballistic correction built into the pistol...but I doubt it.
Airsoft pistols are also horrible target shooting guns. The inaccuracies built into the system are so variable that you can only pick up general trends...not precision target shoot.
At 10' though, the group you shoot should be fairly small. If you are shooting well and the group is small (even if it isn't on the POA) then the pistol is itself accurate...just not hitting where you're aiming
Pistol shooting is a lot less accurate than rifle shooting. The way you grip the pistol, how hard one hand squeezes vs. the other and the way you "pull" the trigger can greatly influence your shot. Shoot inconsistently, poor form and freehand shooting will result in lousy groups. If you're shooting low 6 o'clock, try placing the tip of your trigger finger higher up on the trigger (so you aren't "yanking" the pistol down as you pull). Even on a "straight pull" 1911 you can end up "torquing the shot" by pulling on different parts of the trigger. Long double action pistols are worse for it though. That's not even assuming that you might be flinching.
Only the pad of your fingertip should be touching the trigger, the rest of your trigger finger shouldn't be touching the pistol, you should be gently/smoothly pulling the trigger back until it trips the sear and the pistol fires. You should be able to pull so smoothly and evenly that your sights do not even move on target. The "break" of the shot should come as a surprise.
If your shooting form is good, your group of shots are tight(ish for airsoft), then your sights are off. Adjust them or ditch the pistol because you can't adjust fixed airsoft pistol sights much. (on some you can file down the front sight if it's shooting low...on some you can drift the front or rear sight to take out major windage correction).
It could also be a variety of other issues like the nub being off center on the hopup rubber/bucking...a scratch/cut on the bucking...the inner barrel being off in the outer barrel. Hopup may be applied inconsistently or not at all. Lots and lots of reasons.
If you're in doubt, get someone who's shot a fair bit to give it a try. It's always worth a second opinion.
And...you've got to shoot at least 20' away to see anything significant.