Just wondering if anyone knows why my rear brakes would clunk, bought the vehicle used from family....(sometimes a bad thing), so I didn't really test drive it. When braking to slow down they go clunk clunk clunk until I press really hard to stop quickly (then it stops). And I have no Parking Brake.

And I have no Parking Brake.
That could be the problem.
Have a friend stand by outside then try to duplicate the sound as you drive up to him. Once you isolate the noise, look and feel around for any loose parts. May be a loose caliper etc. or it may not be the wheel at all.