You're going to experience wobble using one hand. The longer you hold the shot, the more wobble. Try to release the shot within say, 8 to 10 seconds. If you can't, put your arm down, take a break and try again rather than force the shot. If you continue to hold and force the shot with a lot of wobble, you will get a "flyer".
Sight alignment is the single most important factor in shooting a handgun accurately. So long as you can maintain sight alignment, you will get off a good shot. Sight alignment is the alignment of the front and rear sights, and does
NOT include the target. You do not have to have a perfect sight picture (front sight, rear sight, and target) to get a good hit on the target providing your sight alignment is perfect. If your sight alignment is off, you will get a "flyer".
A former coach at the Naval Academy used to teach new shooters how to shoot handgun by having them shoot into a blank target. Not having a bull to look at forced the shooters to concentrate on sight alignment. When targets were provided with a bull, the shooters continued focusing on sight aligment resulting in more hits on the bull. This is no "bull".
Maintain a consistent grip. It should be firm but not to the point where your hand goes numb or starts to tremble. The tighter the grip, the smaller the group. More practice will strengthen your hand muscles to where a strong grip is no longer an issue.
Good advice from the other shooters. Keep practicing and you will learn to shoot one handed with respectable scores. Best wishes.