Growing potatoes is the easiest thing ever. As long as you dont have completely shit soil and enough water they will just keep growing. I only did it once in my dads garden and i got a wide range of sizes from pebble to fist sized ones. From a small plot of like 3.5m x 1.5m i got something like 30kg if i remember correctly. Its a single season thing, so wont take more than few months from planting to harvest.