Question
Loved your response of the growing watermelon in a pot, It is extremely helpful. I'm grow a little of everything . Some plants I bought and some I purchased the organic seeds.I bought regular dirt. what can I but to fertilize my baby plants, also everthing I'm growing in large pots, I exciting await your response, Thank You, Cindy

Answer
I hope the "dirt" you bought was good potting soil. I try to recommend the potting soil that has fertilizer and  soil moisturizer in it. Then you don't have to add anything.
Be careful to let the soil dry before you water, so that the oxygen can get to the roots, then plants don't drown from too much water.
I am not sure how large the pots are, and how small the plants are, but one of the problems with putting small plants in a large pot is, that the water is "wicked" away to the sides of the pot, and the roots in the middle are left dry. That is why it is better to start with a smaller pot, and as the roots grow and fill the pot, you replant in the next size larger.
Fertilizer will probably not be necessary if the soil is fresh. I would wait until the plants have had about two months growth, then give them a weak solution of 10-10-10 on a day that is not hotter them 90 degrees.