Can you take it outside and get it up off the floor ground affect will act on the quad till its off the floor , may be now its just a trim problem once its up in the air you should be able to trim it , dont have it in self level mode yet fly in normal mode , some times self level will make quad drift if not set up right p and i gain can also make this happen , once it flys your have to set up the p and i gains
i see your battery is inside make sure when you put it in that the balance is right and if you have a built in pcb on bottom plate that it cant short out on the battery , cover all solder joints so nothing can rub on battery case