Do I need a tetanus shot because of a kitchen grease burn I have.?

Tetanus. You need a tetanus shot every ten years. If you are treated for an injury/trauma (such as a burn), your physician may choose to give a tetanus booster if you can't remember how long it has been since your last booster.
Probsbly not. The bacteria what causes tetanus thrives in deep wounds, so unless your burn was extremely severe you should not need one. That said, tetanus boosters are recommended for most adults every 10 years.