If he/she is new, I would give it some time. It took about a good month for my male to really settle in and feel comfortable. Even still he doesn't like being held too much. It takes time and dedication. What I would do is introduce your hand in the tank by just putting it in there and let your gecko check it out. When he/she starts understanding your hand doesn't mean harm, your Leo may be more willing to come out and near you. If your Leo is new though, give at least 2 weeks before introducing your hand into the tank. They can really get freaked out with changes to there environment and so on. Good luck
You simply need to listen to what everyone has been telling you.
The gecko is young and new and should not be handled for a week or more. It needs to get used to it's new environment once this happens then you can start working on holding it.
We are saying don't handle him/her. Leave your Leo alone for now. You are going to stress your Leo out which will only make it worse and may take longer for your Leo to trust you.
Also, what do you mean by pet? I hold my leo. He crawls into my hand and walks on me, etc. I never, ever pet him. That is intimidating and stressful. Animals don't like that. This is a lizard, not a dog. (even dogs don't like to be pet on the top of the head usually)