Kill a half hour working out and/or go for a jog. You don’t even need weight, just do bodyweight.
Take up hiking, it is nearly free, you get sun and exercise. You can even take a trash bag with you and clean up litter.
Find someone to stalk and murder.
Fishing is a great and cheap waste of time and you get sun.
Find an unsolved mystery in your area and work on solving it.
Start collecting pinecones, cool rocks, or used syringes.
Birdwatching can obliterate free-time and you might meet some widowed GILF to be your sugar momma.
Go places and give them Google or yelp reviews, be derrainged in your writing style like Hunter S Thompson with a head injury.
Take up meditation and have a false sense of superiority because you practice socially acceptable rotting with a calming mentally healthy spiritual guise.
Yoga is a thing, I’m sure you can make yoga pants look great.
Taxidermy roadkill armies don’t assemble themselves, you can even find a tabletop game event to unlease your army upon and meet new people. Worst case you learn about the criminal justice system and that will kill even more time.
Befriend a murder of crows and receive their gifts.