Hi. Previously I had the full creative cloud suite. Recently I had to downgrade to the photography plan to save money, but now i'm thinking of adding back JUST InDesign as an individual app. If I want to do this, will I be able to save pdfs out of InDesign even though I won't have the full version of Acrobat DC anymore? I have just Adobe Reader free version installed now.
You don't need Acrobat Pro to export to PDF out from InDesign.
If you're saving as PostScript file out of InDesign, you will then need to have Acrobat Distiller which comes with Acrobat Pro DC.
Don't use PostScript. Export as PDF from InDesign.