are nutrients needed?

im new to growing so im doing a lot of studying before i grow. my question is do i have to add nutrients or can i just let them grow by themselves in the soil? what do nutrients do to the plant? the soil im going to use is fox farm ocean forest.

No store bought soil that I've ever encountered is diverse and long lasting enough to handle all the nutrient requirements in the cannabis lifespan, so yes, you'll have to feed them eventually. FFOF is good stuff but even it wont take you to harvest. You'll have to make a mix, grow some girls and read the plants as to when they'll need feeding. It's a learning curve, but one most can handle. Good luck.

ive harvested over 15 plants that all i used was organic soil and watered when it needed. How do you think weed grows in the wild? NO one is out there adding nutes to them.
God intended the plant to be on this earth and it is a weed remember
But this year i want bigger yield and am not as worried about the helicopters as they have dissipated due to loss of gov funding(yes!) so im gunna be adding some organic nutrients such as mexican bat guano for veg state and jamaican bat guano for budding to maximize yield and potency

dont feed your plants any nutes for a good 3 weeks try not to use any soil with nutes in it until they reach vegative stage, then start small 1/8 to 1/4 recomended strength