How to waterproof basement walls

scrub down the walls remove grease and dust. There is a product called dry lock that should seal the concrete blocks. Water It still may creep in from window frames etc.

First I would try to figure out where the water is coming from. I would look at gutters, are they clean, do the downspouts move the water away from the house.... cause cheap extenders will help. Do you need a French Drain to move water away from the house.

Once thats done, then I would fill all cracks, holes and crevices. And paint it with Drylok. Remove any efflorescence first with wire brush, and possibly strong vinegar or muriatic acid.

I would also add some kind of venting system to reduce moisture, you can redo a basement window in glass block with a vent in one block. See you tube for videos.

Also check grading all around the home to make sure that land is pitched taller by home and gradually angled downward away from home. After years of home settling and rain or snow packing it down it sinks in towards home making a dam or moat around house or in areas where it wasn't packed down evenly when built or it could be caused by the roots of plants and we can't forget chipmunks that make tunnels around home as well as other animals such as a mole so also look for holes. If you can the next time it rains go out side by the area on the outside where rain water comes in through walls and see if you can't detect the draining process. Can you see it actually going down or if not when rain stops do you see puddles around home close to the foundation. If not dig on the outside by that area (not while it's raining) when dry and see if there is a Crack lower than where the ground is above. Sometimes a Crack can start from the bottom up and if you get water on floors and only occasionally on walls then maybe the crank is below ground in which case you should seal it first by checking the depth and width of it and going to store purchasing outside sealer that is appropriate and a paint that is appropriate for sealing the outside of the foundation following the directions and then proceed to the inside and seal it as they stated above. You really have to back a detective because even the smallest Crack will allow water in if not sealed. You should then make it a practice to check outside foundation regularly because if you have an other Crack the water will come in that way. Water will find its way in your home so depending on age of home it could be the age or if newer it could have been done by a builder that wasn't using the best products available. Good luck.

https://www.thisoldhouse.com/how-to/how-to-waterproof-basement

The question is: "what is causing the walls to weep?" Usually the problem is from the outside. Get a contractor to at least tell you how to stop this problem. Then decide if it's something you can tackle.

You need sealer paint. Go to Homedepot paint department, and ask what's best