take it back and see if u can swap it for one that you are happier with how cheap is it? from what iv read cheap guitars dont have truss rod so the neck cant be adjusted and if your very new to it i wouldnt bother trying yet.
As for the frets you could just file them to the right shape and for the 13th fret buzzing thats probably because the action is wrong and needs setting up properly.
If its a brand new instrument you could take it back and get the place you bought it from to set it up properly they should do it for free since it obviously isnt right