what do I give gods

It depends on the god you would not give Anubis the same offerings and sacrifices as Brigid
Also a sacrifice is not killing it is giving what is hard to give if you are very poor simply buying a candle is a sacrifice. Same as organ donation for some gods like Hela that is something that requires you to give something precious of yours to someone else in her name. (There are things you can donate with out being dead like kidneys, part of the liver, bone marrow and blood)
If you are alright with killing an animal then it really has no significance as a sacrifice. Animal sacrifice was popular in the past because live stock was precious so when it came to a feast day or celebration you would select one of your farm animals and kill it. It served as a sacrifice but what's better is it was eaten in the name of that god at the feast.
Think of it as your Christmas turkey a specially selected animal that is killed and eaten at a celebration.

Lark's post was what I would say as well.

Its really very independent and different to each god/goddess.

Personally I would never do any kind of a live sacrifice. That's just not me, or the deities I work with.

One of the deities I work with is Ganesh. So I often leave him bits of his favorite foods that I pick up at an Indian grocer.