Top left is a prickly pear cactus, maybe Opuntia microdasys. Beware the tiny spines (actually they are called glochids)... they're really easy to get stuck on your hands (or other body part) and then it takes a while to get them out. A memorably bad experience, if you know what I mean.
The other two plants are stapeliads (not cacti, actually African plants) and you will not be able to get much better of an ID on them until they flower.
The cactus will enjoy a much bigger pot over time. Plants like that usually grow into a sort of bush, one pad at a time. For now a pot maybe twice as big as the current one? When you do repot, go in steps about that big, for best results. Make sure the pot has holes at the bottom, and try to use decent potting soil (moisture absorbent, nutrient rich) with some fine gravel (pumice, perlite, etc.) mixed in, maybe 50/50.
The other two plants probably would like a pot twice as big for now as well (same general guidelines). The one in front will get significantly larger than the other. Take a look at these 2 plants (again, no way to know for sure what yours actually are until they flower, these are just sort of representative examples).
All 3 plants like strong light (daily sun) just be careful to give them a gradual stepwise adjustment to direct outdoor sun if they have been in a protected place. Water well and then wait until the soil is going dry to water again. There is no advantage to allowing the soil to sit bone dry for any extended period.
