You don't need fertilizer specifically labeled for tomatoes. You just need a general balanced product and use it according to instructions. Tomatoes need a steady supply of nutrients. Tell me what the two products are that you have and what is in them.
Water the soil from the top, do not water the leaves. Saturate all of the soil. Do not allow the soil to dry out between waterings. Very soon you will need a larger container. What type of tomato it that... determinate? Indeterminate? Dwarf? That determines what size pot you need. Generally, unless it's a dwarf, the smallest recommended container size for a tomato plant is 19 liters (5 gallons).
Finally, tomatoes need to be in full sun for at least 8 hours a day.
