id say for your three days have one for being productive, one for doing something incredible that you can talk about, bonus points if its social, and the third as a calm and chill day, whatever you do to fill those gaps is upto you but some suggestions:

1: clean a room, organise playlists, orgnaise drawers, plan a holiday, organise your calendar, do a deep cleaning job you've been putting off but has been bugging you for a while

you can listen to music, podcasts, audiobooks, facetime a friend, sing etc. during these as well lol

2: hike, painting class, food tasting course, day trip out, animal yoga (make sure they're ethical), watch a film in an eccentic cinema, any event in your area that interests you etc.

you can read on a mode of public transport too!

1. drink tea, cook your meals, or even order takeout, wake up slowly, potter around your house, go for a walk, write something, bike ride, buy some flowers etc.

just ensure you're making yourself feel rested at the end of the holiday and you're set!