What are some cheap ways to loiter in my apartment?

Go to the library, get out some books. Take them home and read them.

@janbb beat me to it. I was also going to suggest the library. They often have more than just books. They sometimes have DVDs and CDs. Some libraries have musical instruments.

Exercise big guy.

Push ups, dips, squats, sit ups, leg lifts, isometrics etc…
I know you are tall like me, but if you can do burpees in your place without tearing up the ceiling, you’ll be one formidable time traveler friend…

Puzzles. They keep your mind sharp.

Pace it all day and get your 5000 steps in.

Play a game of Wordle

See the question two spots lower: https://www.fluther.com/236708/what-simple-thing-not-including-sex-makes-your-day-more-enjoyable/

Paint a lamp post on your wall and lean against it.