Agree with the advice given. As far as the problem with your hands, particularly the left, is concerned, try riding with your hands resting lightly on top of the bars, not gripping them. This helps with using your body to initiate movements/changing direction.

When comfortable with that, just lift one hand (the one you most instinctively feel like using) and counting 1,2...1,2,3...1,2,3,4 etc. until you feel at ease, or reasonably so. Then do the same with the other hand. You'll probably find that it is easier to steer instinctively with one hand rather than the other. For most people, this is the left.

Then follow the other advice to do this with obstacles on a flat surface (car park, etc.). Whether using one hand or not, try to get the feeling of "swinging" the bike with your hips/body around the obstacles (6'/7' apart is a useful distance to start with) rather than steering with the hands. And do so at a consistent speed.

Other than this, practice, practice and more practice. Also, try and concentrate on the manoeuvres you wish to do and not how to do them. Your instincts/subconscious will be able look after the how within a very short time.

Good luck and welcome to the family, fractious tho' it can be at times