Put nothing on the inside of the walls (e.g. paints of any sort). They will do nothing but bubble and peel and make any future work more difficult. You have to alleviate on the outside. Make sure your downspouts have leaders that discharge water as far away from the house as possible (10' +). Make sure grade is sloped away from perimeter at minimum 6" in 10'. Other maintenance things like keeping gutters clean and no buildup of mulch/stone against the house or creating bathtubs. And just to note, in an old house with brick foundation walls, there is no repairing walls against water intrusion, you'd have to dig outside and put waterproofing and drainage.

Your seller disclosures should have said something about known water intrusion.

Since your other post says you have a gutter problem, maybe that should be repaired sooner rather than later. Some of the water, may be coming from leaking gutters. Please check them all the way around the house. Make sure the downspouts have extensions on them to run all the water away from the house.