If you're going to grow cannabis, you're going to have to learn how to transplant. If you start the plants in too big of a pot, the tendency is to overwater, which can kill or stunt a seedling. The moisture in the larger pot lasts longer than is desirable for seedlings. Use care when using the smaller pots though. They tend to dry-out quick. But this is ok, because it's easier to add water, than it is to dry-out an over saturated pot of soil. If worried about errors in your transplant process...plant more seeds than you need as back-ups, and practice.

Start them in smaller (2-cup?) cups that have drainage holes. When they start to get rootbound, wait till the soil dries-out, prepare the new pot (next size larger) with fresh soil, carefully pop the rootball (turn upside-down, and give a gentle tap or two) out of the smaller cup and transplant into the new pot. Finish filling the new pot with soil, but don't compact it down. A gentle push on the soil, but don't get heavy-handed. Water with properly ph'd water, and add more soil to the hollows, as it likely sagged when you watered.

Most nurseries have a section of used pots. (black nursery pots) They're cheap and work great, and are available in sizes ranging from a starter cup, to one, 2, 3, 5 and 15 gallon sizes. The sizes I use are the small starter cups, one gallon, 3 gallon and the 5 gallon.

One bulb is really insufficient for anything older than a seedling. It can be done, but at a huge price. (plant size and stretching)