My approach to basements is assume it'll get wet at some point and operate accordingly. Especially if you know it does get wet. So don't use flooring that is going to be ruined by water. I didn't know vinyl was susceptible, but guess I was wrong.
As for the leak - standard approach is to make sure your gutters are clean and functional, downspouts are draining far enough away from the house, and grading is appropriate so that water flows away from the house. If you have a sump pump, make sure it's operating properly. If that doesn't fix things, then it starts getting very expensive.