Imagine how much fun it is for him to see that he can fly!
I wouldn't clip his wings because he's at the age when they learn to fly and if they can't they may never learn. A very conservative clip (trimming only the tips of the flight feathers a couple inches or only trimming a few of the flight feathers on each wing) is an option but a more extensive clip will make it impossible for him to learn and he will hit the ground hard and could injure his breastbone (keel).
Learning to fly involves some mishaps. They don't know how to stop, turn quickly, land gracefully etc yet. They have to learn by making mistakes.
Unless he gets up a lot of speed while learning he isn't likely to injure himself badly. It's best if you let him learn in a small room that has windows draped and mirrors covered so he doesn't get going too fast and doesn't hit the glass.
Once you have him flying better, I'd bring him over to any windows and teach him that they're glass by knocking on them. Birds do learn the glass areas in a room pretty quickly if you do this.
If you're going to let him outside without a harness and without his wings clipped you run a very high risk of him flying off in a gust of wind and getting lost. Please don't take chances with him! He will DIE out there if he gets lost!