If you played an instrument when younger pick that up again or learn a new one.
Revamp a room/some furniture.
See if your local library or even an online book club.
Have a look at, free, online short courses. You can do history, art, science.
Local music/arts gatherings.
Talks at galleries.
Your local Facebook pages might be your starting point, local press/radio.
Spend all day trashing the kitchen with radio on making tapas, or something similar, lots of small dishes.
Master a difficult pudding, fancy cheese or yogurt cakes.
Invite a long distance friend to stay.
Build a garden firepit or pizza oven.
Get face/foot masks and truly indulge and pamper.