There are 3 main components to plant fertilizers; Nitrogen (N), Phosphorous (P), and Potassium (K). Depending on what stage of growth your cannabis is in, determines the nutrients. If you use in-water nutrients, be careful of how much and how often... reading the label could help prevent harm to your plants. I only water with nutrients every-other watering when working with soil. you can find decent nutrients at any garden center but if you want the nutes the pro's work with you will have to make a trip to your local hydroponic indoor gardening store.
As for the soil here is my favorite mix:
1) Mix in the portions of 50% pro mix (regular soil), 35% perlite and 15% vermiculite. This mix is nice and loose and will promote great and fast root growth. All though it doesn't retain water that well it is good for beginners because it will help safeguard against over watering. Plus if a beginner runs into problems with PH or over fertilization the properties of this soil make it quick and easy to remedy.
Lastly for a new gardener like yourself take the advice of legendary grower SeeMoreBuds:
"It is of great importance that the grow is done safely, and with enjoyment. Do not let the growing process bring negativity into your life, regardless of frailer or success. Everyone experiences unexpected broken branches, bug infestations and other obstacles. Remember that you are growing for enjoyment and you are in control of your own happiness"