You only need either the ACT or SAT.
I was accepted into Purdue with just a 3.4 high school GPA and no advanced or AP courses because my school did not provide them (kind of a small school).
I decided not to attend because the school is just way to big in my opinion and if you wan't to study aviation there are cheaper schools out there that teach you the same thing and don't have any sort of space issues like in Purdue or Embry-Riddle. Not naming any in particular but its not worth it in my opinion if you just want to be a pilot. However if you wan't to be an engineer, Purdue is a great school for that. Engineering is the only program I know about that Purdue does well, but I don't know about the other programs.

But just so you know, Purdue accepts 72% of its applicants and 9% has a GPA between 2.5 and 2.99 so you should not worry.