I'm more of a heavy compounds guy, but I do know a thing or two about calisthenics.
The bread and butter of body weight are Pushups, Pullups, and whatever core work you try to do (there are tons, I prefer planks and leg raises). Dips are probably the next big thing, but some people don't like them (fuck with your sternum sometimes).
So if you are looking for something super basic, I would say 4 to 5 times per week do 100 pushups, 30-50 pullups (you can break both of them up however you want, I usually do my pushups 40/30/20/10 with about a minute in between). and then do your core stuff. You want to be able to hold a plank for 2 minutes, but if you can't then do it for one minute, rest, then do another minute. Crunches tend to be boring and repetitive so I avoid those. If you go to randomabs.com you can find tons of stuff too.
If your cardio is running or cycling and all you want is ottermode, then that is enough for your legs. That's about as basic as it gets, but still beneficial. In my opinion though pullups are by far the most beneficial bodyweight exercise out there, so really get into those.