See how those rear dropouts are paper thin? See how the fork doesn't even have a discernible dropout, instead just a crimped and notched fork leg?

Yeah, not worth putting too much energy into, leave it as it is, get hooked on riding, ride it into the ground and then pick up one of the <$200 FBM/EASTERN/KINK craigslist specials that pop up whenever a BMX rider gets old enough to buy a car.

FWIW, no bmx of any quality will have a QR seatclamp.