New Grower, Looking for nutrient/ammendment suggestions

Hey all, first time grower here. I've been researching everything and everything I can the past week about indoor cannabis cultivation, and what I've found most intimidating so far is what soil and nutrients to use, as well as watering correctly. I purchased a 30L bag of Gaia Green organic lving soil 1-0-0, and a bottle of GO Biothrive Grow and Biothrive Bloom. I'm not sure if I have everything I need as far as soil and nutrients, do I still need Cal Mag? and are dry ammendments necessary as well? Any advice would be appreciated.