•~• my 1st grow •~•

The pots are tiny, you should aim for 15-20L unless growing really tiny plants, so yes, definitely repot. If you have compost based growing medium then you do not need to feed them for a while (read what your compost bag says). If it is very nutrient rich, then you may have enough nutrients to go without extra ones for a month or even longer. The leaves look healthy so your lights are fine, they are not burning them. Most plants usually take a pause in week 3 before full veg phase starts and they begin to grow like mad so be patient. Good luck!

Sticky traps to catch the adults and apply a coating of pumice to cover the soil, specifically the size commonly sold for the bonsai hobby. Pumice is a lightweight stone that due to its porosity is able to absorb excess moisture. When layered on top of the soil, it makes passage in and out of the top layer of soil much more difficult for the fungus gnats and can deter or prevent them from laying eggs. If using this method, wait for three weeks before removing the pumice to ensure that the fungus gnat life cycle has been completely interrupted. Some people will use neem oil, but I always use caution with it as it can make your buds taste awful. So only during veg is best and never put it on the soil. Another method to kill the eggs is to use a mix of hydrogen peroxide and water. But since your in soil it might do more harm then good by killing all the good bacteria as well.