If you did not get an owner's manual with the bike do the following:
First: Look all over the bike to find the maker' nameplate.
Then: do an internet search to find the owner's manual. When you get it read it and understand it. Also go to your local library and read up on two-stroke engine theory.
Could you post a photo of the bike so we could tell what model it is? Also, go to the photo section of this site and see if there is a photo of a bike that looks like yours.
Does it have pedals like a bicycle? If so, it is a moped. If not it is a motorcycle.
Stat off the public roads until you are of a legal age to ride it. You do not want to get stopped by the police and get your unit impounded.