Carrots, mixed leaf lettuce and tomatoes 👍 But would need to know how big a pot you have....
All very cheap to buy as seed and have about 60 - 300 seeds per packet, so you can sow lots and stand a great chance of growing something.
If you've just got 1 pot, I'd go for mixed leaf lettuce and grow a few varieties in a single container. Simply fill to the top of the pot with loose soil, then compress down (should leave it about an inch or 2 from top), scatter seeds and then top it off with 1/2inch of soil.