As has already been mentioned, I'd advise steering clear of ALL the Chinese stuff; I've heard several bad accounts regarding the spares availabilty etc for them, and I've seen quite a few with very bad rust problems when only a few months old. (They may be cheap, but they're cheap for a reason).
Plus, it's my belief that you'd get very little for it when you come to move on.
It's many years since I started riding, but when I did, I started on a Yamaha RS100 (they later called it the RXS100) - it's a nippy little two-stroke, and I found it to be ideal as a first bike.
Here's the financial rub - Yamaha also did an RS125 which was almost identical to the RS100, except it had a tacho (the 100 didn't), and it had a front disc brake, while the 100's was a drum.
Sure, there WAS a couple of MPH difference between the two, BUT - the 100 cost HALF as much as the 125 to both tax AND insure...........
Having said what I've said though, I will also agree with Dooffle that a four-stroke might be a better bet.........