The antifreeze and the coolant – they’re the same stuff. You’ll want to take a careful look around your engine and check to see exactly where the leak is coming from. Hopefully it is just coming from an old hose and not your water pump.

Either way, you’ll want to get your owner’s manual out and find out where the antifreeze/coolant resevoir is and check the level – much like checking your oil level. You can buy antifreeze/coolant at any auto parts store – be sure to check your manual so you buy the right kind (it should all be pretty standard, but you wanna be safe).

They sell ready to use antifreeze/coolant that you don’t have to dilute with water, just add it to your car.

Sorry for the maximum verbosity, but as luck would have it I’ve been having some problems with my coolant/antifreeze level myself these past few weeks. And on my first car I split a hose, loosing all my coolant/antifreeze in the process, and (at a different time) had my water pump die. Fun times the both of them.