I just picked up the wrong jug and put about 1/2 gallon if that much of weed eater gas/oil mixed in my riding mower. I have not cranked it yet because I noticed it was the wrong jug. What do I do now without messing it up?

Hi,
I would not worry. I have disposed of two-cycle mix this way rather than have it go bad.
Peace,
Clarke

You may have some plug fouling and a little smoke but you won't damage the engine. If you are still worried, get a kitchen baster, suck out what you can and add regular gas.