No need to go to a 3 gallon pot. A 1 gallon will be plenty big until you get ready to flower and then only if you know the sex of the plant. By going to a 3 gallon pot you will only be wasting potting soil.
I don't know where the notion of putting seeds on wet napkins to germinate came from but it sure is not natural. All you really need to do is take a 16oz plastic cup poke a couple of holes in the bottom, fill it 2/3 full of potting soil, drop a seed in a hole 1/2 inch deep, water with 3-4oz of ph'd only water and place under your favorite shop light. Just spritz the surface of the soil with ph'd water everyday for 3-7 days. If the seeds are viable they will germ no problem.