I think what you are asking is what are the essentials and what are more supporting things that will enhance the basic needs of the plant.
Basic needs of the plant? Light, water. soil(or whatever grow media you want to use).
I live in a part of the country where there aren't stores that cater to growers(Hydroponic stores) so I order all my supplies online and have it delivered. When I lived in California and worked in licensed grow ops, Hydro stores are on practically every corner so hydro supplies were easily accessible.
For soil I like Fox Farms but have had better success with Root Organic Original. Both are good but, again, I prefer Roots to Fox Farms. I've grown in pretty much every media you can think of(Coco, Soil, Hydroton, Perlite, Rockwool, etc.) and I always come back to soil. For me soil has a particular taste that I don't get from the synthetic media. It's probably just a figment of my imagination but it is what it is. BTW I disagree that growing in soil will delay your seeing issues. As long as you're diligently watching your plants, which you should be regardless of media, the leaves will tell the story immediately. IMO, soil is the most forgiving of all the media because you can underfeed and still give your plants the nutrients they need through the natural soil processes. Growing in synthetic media you need to be much more on top of the girls because any mistake gets amplified since you don't have a natural backup that can fill in whatever you are lacking. If you're a pro grower then the other medias have their pros but for beginner growers I always recommend soil first.
Same with nutrients, I've used pretty much every boutique nute that's come out in the market in the last 20 years but always come back to either GH 3 part for larger grows or GH Florinova for small and tent grows. For small and tent grows you don't need to spend the extra money for the fancy nutes because an increase of 10% isn't going to be worth the money you spend on all the nutes and amendments but in a large grow op 10% can mean hundreds of thousands of dollars. Florinova is cheap and very effective. Several Cannabis Cups have been won with growers using Florinova. While nutes are important technique, skill and experience are what will give you consistently large yields. At one of the licensed grow ops I worked at the botanist did a comparison. Same strain cloned from the same mother so genetics were identical. Both were grown in 6" Rockwool Cubes using a basic flood and drain irrigation setup. We had test tents to test out new strains and cross breeds before we put them into production. He watered each clone with nutrients from different nutrient companies. He used Miracle Gro tomato formula on one and Advanced on the other. The Advanced plant was slightly larger but dry weight flower yield was almost identical. Plants don't care if the food you give them is expensive or not. It's food. That facility used nutes from
Dyna-Gro.
Same with lights. Large grow? Yes, those expensive
Gavita double ended lights will boost your crop meaning the investment is worth it but for small grows the incremental gain you'll get is not worth the investment along with all the other stuff you need to be able to extract the heat that lamp is going to generate. I've been using
Bestva blurples for home and tent grows with great success and they're half the price of the high end LED's like
HLG. Don't get me wrong
HLG's are great lights and will give bountiful yields but how much better are they really? Are they going to boost your yields more than 20% - 30%? Unless you are a highly skilled grower that knows how to use the higher canopy umols you're just wasting money. Think of it as someone that just got their drivers license and is given a race car to drive. That person won't know how to use the car to his advantage regardless of the power they have underfoot. I have a
Bestva Pro B2000 on it's way for my 5 x 5. Great light at a very low price.
Supporting things for me would be like particular amendments that are better suited for large grows for the same reasons I outlined previous. Two circulating fans in the tent rather than one? Great to have but not critical. I've seen people do great grows with nothing more than an umbrella light, Miracle gro and some plastic sheeting! Start with the basics. Learn how they work and how to push them to their limits. When you can't get any better bring in the other stuff and see if it makes it better.