I'm really new to biking but it's been a bug that bit me and boy did it bite me hard, haha!

Sometimes, if I see a nice bike parked there all sexy, my hands get itchy to touch it. I'm really excited and I can't wait to learn more about bikes!
I've read the threads for beginners and I like the Ninja 250 which I've read are commonly recommended as a starter bike. However, I'm 5'1 and I weigh 100 lbs. and so I wonder if there are any suggestions you guys can give me on if there are any better bikes out there for my weight/height? Or just any advice you can give so I can prevent from .. just getting smushed? Thanks!