If you're just interested in general fitness, no equipment needed, there are any number of online workouts to follow that will give you a great whole body + cardio workout using nothing more than your body weight.

(though I bought both a spinning bike and a set of dumbbells at the beginning of quarantine... I've finally reached the point where the dumbbells aren't quite heavy enough for everything, so I've been watching eBay for a good deal on additional weight plates since as you noted, it's hard to find workout equipment)