I'm throwing my 2 cents in late in the thread, but here's how I see your situation:

You were not comfortable with yourself through high school and college, felt like you didn't have the looks/image that girls desires, felt out cast.

Now you've come into yourself, got your looks going for you, got in shape, and feel ready to be with women. You want to feel validated now. You want those attractive girls to want you. Your self-esteem longs for this, and I completely see how understandable this is.

You want to sow your oats. You want to date attractive 'hotties'. Of course, you have no experience, you have emotional scars from your youth, and you are scared of rejection.

My advice is just try to relax and go with it. Don't tell anyone you are just interested in sex. Show the best of yourself. You say you want to impress the girls. So, impress them. How can you do that? Have some fun. You deserve that.

In time, you will be ready for a meaningful relationship and it will happen naturally. For now, part of your motivation is you are trying to repair the scars of your younger self.