I turned my mower upside down w/o draining the oil. It leaked out from somewhere. Dipstick was in tight, so where did it come from? There was quite a lot.

It probably came out of the oil breather, muffler or carb.

Dip stick don't usually fit that tight. Turn it right side up let it sit for a while. Try to start, probably won't. Remove plug, wash in gas, let dry. Reinstall plug and try to start again. If it won't start remove carburetor, dip in container of gasoline. Try to get a little gas in intake port. Reinstall carburetor.

Don't turn upside down again, it ain't no airplane engine.