I did not wip off all of the excess stain when applying and was wondering what steps I could take to remedy the situation?

Also was wondering if mineral oil will raise the grain on my floors? They are oak.

Any help is greatly appreciated!!!

Since wood is pourous, the stain is probably all uneven sitting on top.
Easiest things to do is use a white polish pad for your buffer. Pour paint thinner all over the pad and start buffing. It will loosen all the caked on stain up and bring it down to the stain that already filled the pores of the wood. Then follow with some rags/towels to wipe up the excess.
If sanded correctly, when you do this it should like nice and even
good luck

I've heard of applying more stain and then wiping/buffing it off ASAP.

I have no idea if it actually works.

Some stains are self dissolving, meaning when you apply more, you re-activate what's there and are able to work it again. But some, after fully dry, won't even react to mineral spirits. It's one of those situations that you try different things till you find what works with the product you used.