Leaking on the floor or near wall?

If not major, it can be just DIY or simple job. Nowadays you can buy liquid to be poured on the flooring and let it flow in cracks and plugged the leakage.

The original floor, the water proofing substance is mixed with the concrete during construction. Simple one in olden days would be painting the floor with water proofing solution before a layer of cement and floor tiles. This method is used on the wall as well to certain height (maybe about a foot).