were do i start first finished my car fri,thought i would be able to spend all weekend at the track getting the dust off wrong

now i im trying to break in the motor but the only way i can get it to start is to put fuel in the carb, and then when i give it gas the wheels well not move as well as i can not keep it idling r to start back up. i have taken it apart and put it back together several times and i keep getting the same

the wheels well not turn when i give it gas. the breaks r not engaged what am i doing wrong