Looking for guidance with leaky foundation
The solution is simple, likely just not easy.
Find the source of the water and eliminate it.  For basements the usual sources are rainwater not being drained away from the foundation walls, or groundwater.
With rainwater, your best bet is to ensure that all of your gutters and downspouts are in correct working order and that the downspouts drain in such a way that the water is carried away from the structure and can safely drain off your property.
Groundwater is more difficult and to fix it properly you need to address the basement drainage and sealing from OUTSIDE.  Chances are this property either doesn't have a perimeter drain or it's failed and the walls are not properly waterproofed.  The usual solution is to excavate around the outside down to the footings and install a perimeter drain and then apply an appropriate sealing system on the outside that allows water to drain to the bottom and also prevents and infiltration into the basement.
The final part is a properly installed sump pit and pump to take care of anything that makes it past the first two lines of defense and also takes care of any groundwater that is coming from under the foundation.
There are no shortcuts if you want this done properly.  From the looks of this the problem has been going on for a long time, perhaps since the property was built.