trying to start page numbering on page 3.
This is a quite ambigous post. Either you want to have page 1 showing a nubmer >1, which is a different thing than starting page numbering on page 3 with number 1 (or with number 3), while pages 1 and 2 just don’t show a number. Thus as usual - asking a good question is essential to get a good answer.
From the documentation: To Start With a Defined Page Number.