Get a chin up bar. Chins/pull-ups, push ups, sit-ups/crunches, pistol squats.
Discussion
Got one of these and a chin up bar upstairs. Pull-ups and chin-ups are the toughest/best upper body workout IMO.

Ah a climber! Nice! Boulder or routes?
I like both but prefer bouldering. Haven’t gone in 2 years though because I had a shoulder injury and then slacked on getting back.
Eager to get back out there soon. Was supposed to go last weekend but that fell through.
Did this for about 10yrs, it works quite well.