About How Much To Finish A Basement Floor?

I have a basement that leaks from the ground up and if i dont plug the pump in it will flood but even if i do plug the pump in the floor gets wet from the cracks. I need to know what to do to seal the floor or something so this wont happen. The basement was once kept up with a couch rugs ect, but when the old tenents moved out they “FAILED” to tell us we needed to connect a pump…..
So 2 sum it up….
1) What do i have to do to seal the floor myself?
2) How much would it APPROX. cost to get it done!!
I have Approx 1000sq. basement floor!!
Thanks