The first few days after the plant has leafed out are a very exciting time, especially for beginners. The most important thing during this period is to let the plant grow a little and not experiment too much, as beginner "parents" are often very protective.
If you have planted them in large pots then you will probably not need to water them for the first few days or even a week. For the time being the plants take in very little water, this will change as more leaves grow and evaporate through them. Check the humidity with a finger - put it 2 cm deep into the soil, if it is wet then don't water. If it is dry, add water slowly until it leaks into the base of the pot.
For the first 2 weeks we don't water with fertilizer at all, we do it only after 14 days, and even then the first fertilization should be with a reduced dose of fertilizer to half. Subsequent watering already with the full dose of fertilizer. During the vegetative phase we water with fertilizer appropriate for it, and then when the plants begin to bloom we switch to a fertilizer for flowering.
One thing that can happen in the beginning is that the plant stretches out (long stem and no leaves). This means there is not enough light and the lamp needs to be lowered. It should be about 30 cm above the young plants, later it can be less, even 15 cm from the top depending on the temperature.
For the first month we also need to keep the humidity in the growbox at a high 60%. We can do this easily by placing trays of water, you can put cloths in them to increase the evaporation rate. After a month, when the plants begin to bloom, the trays are taken away, so that the humidity drops to preferably 30%, otherwise you risk the appearance of mold on the flowers.