How do I stop a leaky basement?

Ours was a foundation problem that existed when we purchased but was covered up by the sellers. We found out about 7 years after purchase when we started remodeling basement (had to know within 5 years in order to file lawsuit) I would suggest you get a contractor come look and let you know what should be done.

There are lots of things you can do, depends on where the water is coming from. If the water table is high and its coming up through the slab, you seal the concrete floor, then if its really wet you might need a sump pump. https://www.youtube.com/results?search_query=how+to+seal+concrete+floor+from+moisture

If its the concrete block walls that are damp, you can paint the inside with Drylok paint and/or if the water is coming from a hillside draining down to your foundation, you may want to put in a French Drain with catchment basins to move the water out to the street storm drains. If you decide to put one along the foundation, I would also paint the foundation and footer with rubber waterproofing. https://www.youtube.com/watch?v=v4BPuil3S2o&t=116s

https://www.youtube.com/watch?v=MhW2fU45JK8&t=95s if you go to his page he has lots of videos on how to do drains, sump pumps etc.

If you get a lot of rain where you live, gutter extensions to move the water out into the yard works really good. And make sure your gutters are in good order an cleaned 1x or 2x a year. This solved my problem.... https://www.youtube.com/watch?v=rT6ZUWXsYgQ&t=42s

Where is the leak coming from and how bad. Different ways to handle this.

Use hydraulic cement to fill the cracks. It expands as it hardens. Then use Drylock waterproofing paint on the block. It absorbs into the concrete/block.

Turn your water supply off, find where the water is leaking from, then fill in the holes with corks.