What can i use as lube(for my asshole)?

Solo play? Basically anything that won't irritate skin, but you'll want to get an actual lube for long term use. There's plenty that won't really hurt you if you use it once, but you won't want to make a habit of using things like lotions meant for the outside of your body. If you get that desperate and refuse to go to the store, look for things with as few ingredients as possible, with as little scent as possible. Many lotions will have warnings about not getting them into orifices, do not ignore those warnings as they are usually heavily scented or have high alcohol contents, they might burn on delicate tissues.

Glycerin is the main ingredient of most water based lubes and will work fine. Aloe vera gel is the main ingredient in many "sensitive skin" lubes and will also be fine for at home use if it's nothing but aloe and preservatives (but not hygienic if it's straight from the plant.)

If you're not using latex at any point, a skin safe plant oil would be ok for a single use, you just don't want to make a habit of sticking coconut oil or something similar in your butt every day.

Baby oil

dad likely has some lying around

I use lotion or baby powder