Water Leak

Where is the freeze plug loacted on a 1995 Buick Century?

THE freeze plug ?

There are many.
Probably six of the same size, three on each side of the block on who knows what size engine.
Others on cylinder heads and front or back of block.

Clean first to see what’s leaking.

On a car that age if one is rusted through, the others aren’t far behind.

Freeze plugs are pretty much impossible to see looking down on the engine. If you get the car up on a lift you might be able to see one or two freeze plugs if you can get an unobstructed view of the block. There are likely 6 or more freeze plugs on a V6. They are usually about 1" diameter circles that look like indentations about 1/3 of the way of the block from the oil pan.