The size of the pot affects the size of the pot plant. In bonsai gardening, a small pot is used to help keep the tree miniaturized. While growing in a 2 gallon pot is certainly do-able, you will get a better yield with a larger pot. Have you checked the local Dollar Store for buckets and waste baskets (anything over 8 quarts will be more than 2 gallons) or get a few of those 5 gallon buckets. Add a hot nail or a drill to make holes and you have pots! About watering, fill 2 pots with soil. I want you to wet one completely- I mean, you can't get it to absorb any more water at all, totally dripping. (You might want to do this outside or in the tub.) Now pay complete attention to what you are doing, you will have to remember how it feels, later. Pick up the dry pot. Your pot should NEVER feel like that. If your pot feels like that, your plants are dead! Pick up the wet pot, feel it's weight. Now just about half way between the two is when you start thinking of watering. Observing your plants will fine tune the timing. Are the leaves dry and papery feeling? Are they cool and flexible? Are they just soft, or are they getting floppy and on the edge of wilting? Use your eyes and hands to help you judge when it is time to water. Feel the soil, stick you finger into it. You may want to just use one spot and re-cover it with dirt; poking around in the soil disturbs the root system. I put a spot of paint on the pot to mark my poking place. Make sure you have the best soil you can create, no matter what size of pot you use. Grow organically, you will be eating, vaping or smoking this stuff, so you want it as safe as possible! As soon as possible, get a vaporizer and save your lungs! Tell no one that you grow. Live long and prosper!