Look for a really cheap, 90's ANYTHING between a 125 and 200cc. 2-stroke.
Don't get a new bike if you're a noob... you'll kill yourself.
Especially if you've never ridden... you may hate it, then you're thousands in-the-hole.
Go to Craigslist.com and look around... even pick up an auto-trader or want-ads or something in your location...
Don't spend over 1000 dollars for your first bike because you'll break it, or it'll break you.
Just my $.02
Good luck.
Dan