I don’t know why, but I have a feeling that if I do PSEO I won’t get any scholarships, is that true?
I don’t know where you got the assumption that you can’t. Post-Secondary is just you looking for more challenging courses not offered by your high school. Honestly, it would probably bolster your chances getting a scholarship.
Do you have a particular reason for thinking this? I took nine university classes through PSEOP in Ohio. (This was in 2013-2014, and the program is called College Credit Plus now.) I got large scholarships from many public and private universities.