Guinia pig food is pretty cheap at the grocery store.
*shrug* food, water, don't freeze or bake, and keep the environment relatively clean (wood shavings work fine, but ceder causes cancer, so go for white pine)
You can call the local animal shelter. They should be willing to take it.
Personally, I think Guinia Pigs are cute and fun. Were I you, I'd head down to the pet store and get a nice cage (guinia pigs should have the wide, flatter cage's. If it has a second story, the ramp should be a pretty gentle slope) water bottle, food and alfalfa (they like alfalfa)