2000 monte carlo

Water leaks are tough to find, but I usually peel the rug back, or remove it, and have an assistant run a hose over the car while I examine for leaks, Troubled spots are around windshield, doors(rubber wheatherstrip) And electrical connectors that pass thru the firewall. You need to get up under the dash with light and look for signs of water.

do you think its something major like blown head gasketor heater hose can i still drive the car?

Does it smell like anti freeze? Is it sticky? Or is it just water? If it's water intrusion, it can be driven, if it's antifreeze, the heater core is leaking and should be fixed before driving it...