To get up to something = to do something (usually something negative or mischievous, in a fun way). My brother is always getting up to something when he's out with his friends. We got up to all sorts of fun things when we were in Rome.

Amanda has a good point. It could be a typo: "get up to snuff." In the United States, we sometimes say, "He is not up to snuff", so "get up to snuff" would be a logical variation of the idiom probably in use here too. I am not particularly keen on the expression since "snuff" also means tobacco.

Lewis is right about "get up to stuff." Just in case you meant "get up to snuff" that is a British phrase being to be up to standard. "The English exam is next week so you better have your grammar up to snuff."

I haven't heard that exact expression in the United States. Perhaps it is specific to other countries or a younger generation. These two similar expressions come to mind: "You must be up to something" -- mischievous, as Lewis suggested. "You must get up to speed" -- you need to learn something, develop skills, etc. in order to be at the level that you should/want/must be at.