Were to leave your hands while presenting in front of an audience is not something that has an easy answer. The question where not to leave your hands while presenting is much easier to answer: Do not leave your hands in your pockets. If you come on stage and have your hands in your pockets it won’t look good for your audience.
Presenting with your hands in your pockets will leave the impression of a form of disinterest. And if you appear not to be interested, why would your audience be interested and what you have to say? Obviously there are different things that you can do an should do on a stage to feel comfortable, but it is better not to have your hands in your pockets. This is true for two hands but also for one of your hands.
Have a look at the book that is part of the Public Speaking Kit in which you will find multiple tips and tricks about the do’s and don’t in regards to standing in front of an audience and presenting your story in the best possible manner.