Quadrupedal movement(i.e. crawling), a resistance band routine and pullups will hit everything strength and mobility-wise, and cost and weight are close to nothing relative to a full gym. For pushing the intensity even further you can add a weighted vest or just stuff a backpack with books, with some padding to keep it stable. But you only want to do all of that a few times a week max, because it's very strength-focused and will overtrain you quickly if you let it; for the majority of sessions, a warm up to work through any stiff joints, and then cardio, is the right amount.

For cardio, it's a matter of "pick your poison". Some people like the bike or rowing, some have found a traditional sport they can practice like shooting a basketball, or a video game like DDR, Beat Saber or Ring Fit. Many people have gone for a treadmill desk or stepper machine. If you're doing boxing, maybe the classic speed bag and jump rope will do the trick.