Would being in a Police Academy be a full time student?

It depends whether your Police academy is an eligible educational institution.

If it is, you qualify as a full-time student if you have attended for at least 5 months or part-months in 2021.

You can use this IRS link to check if your academy is an eligible educational institution.

Q. Would being in a Police Academy be a full time student?

A. No. This assumes you were a paid employee while a cadet.