* "Too" as an adverb meaning "also" or "in addition": There's no exact homonym for this meaning.
* "Too" as an adverb meaning "excessively": The closest homonym is "two". However, it's important to note that "two" is only a homonym in some contexts, like "That's too much" vs. "There are two cakes".
It's important to use the right word based on the intended meaning.