1996 Honda Civic Coolant

There's a dozen places coolant can leak from. You're going to have to hold your computer closer to the car so I can see it, ... OR, ... You might consider adding a small bottle of dark purple dye to the coolant, then search a day or two later with a black light. The dye will show up as a bright yellow stain that you can follow back to the source. Auto parts stores will have the dye, and those that rent or borrow tools should have a black light.

This all assumes there is a leak. Since you don't know the history of the car, the coolant level may have been low for a long time and isn't going lower. Before you get too excited, wait to see if the level drops again.