First time grow!

Firstly wait until your plant(s) have entered the vegitative stage. You won’t need to add any nutrients during the seedling stage and by adding nute you could stunt your growth and give them nutrient burn. The soil you are using will provide enough nutrients for the seedling stage. If you are using FoxFarms soil I would say it’s best to keep with their nutrients. They are relatively inexpensive and I have personally been using them and they have been great. FoxFarm also provides on their website a great feeding schedule to follow. If you have any other questions I will check up later. Good luck on your grow!