Start with soilles. Avoid "marijuana" brands. They too often reinvent the wheel and make it square for no reason.
Soilless is the easy button for excellnt grows, immediately. Short learning curve, better growth rates, good results with limited effort. Since you control everything that goes into the plant, you can more easily adjust to what you see in precise and accurate ways. It is less of a guessing game if you keep good notes.
bruce bugbee/ apogee instruments on youtube is an excellent source of info
Dr. Photon's Corner on cocoforcannabis.com is another excellent source
When you find things that contradict what these 2 sources say, be skeptical. There is a shit-ton of absolute bullshit out there. bunch of fart sniffers, LOL