For my school project for graduation, I need to collect comments and posts from Facebook groups and pages to do sentiment analysis on them. Please note that I don't own any of thoses groups or pages. As far as my understanding goes, I need an access page token for every single page and group and I need to submit an app for review. Since it's a data science project, I don't have an app to submit for review. What can I do to collect comments and posts without an app? I hope my questions are not stupid, I've been searching for answers to this for weeks, thank you.
"without an App" - not possible and not allowed. Facebook specifically forbids scraping.
You can use an App Token though, with Page Public Content Access: https://developers.facebook.com/docs/apps/review/feature/#reference-PAGES_ACCESS
Keep in mind that you have to get your App reviewed for that. Afaik there is no way to get comments/posts of Groups without managing the Group though. Check out the requirements: https://developers.facebook.com/docs/graph-api/reference/group/feed#readperms
The app must be installed on the Group.
(which is only possible as admin)
You would definitely have to go through Review too: https://developers.facebook.com/docs/graph-api/changelog/breaking-changes/#groups-4-4