basement dampness

Hello i want to start studding my basment walls i know basments aew damp and some of them actually het water seepage. I dont or havent seen any signs of water in my basment i do have effloreance though. I did notice some damp spots on the floor where the floor meets the wall. Is that something thats normal with a house that was built in 64. Is it a a majior problem ir i can go head and install a vapor barrier or foam board. Is this bigger then im thinking where i have to dig trench around home and fix from ourside?