The pst should be in the local app data folder under microsoft\outlook - shortcut to get there is %localappdata%\microsoft\outlook - type or paste it into the address bar of file explorer then press enter. This will open the folder where the pst is.
Do you want to archive to the 2016 pst or use it as the default pst? Calendar & contacts, categories, custom views are in the default pst - you can move appointments, contacts, tasks, and notes if needed, but categories and custom views are more difficult to move. My recommendation is to use one pst for new mail and archive to 2016.pst, rather than setting the 2016 pst as the default. You can choose the pst in the autoarchive configuration in Options or in the manual archive dialog.
FWIW, unless you get a lot of mail each year (multi-GB), i wouldn't archive - it's easier to use one date file.