It depends on what you are after, how much space you have & your budget.
My gardening is a combination of the expensive & the cheapest of the cheap.
Honestly I think they both produce fantastic results.
When I have money I am a sucker for Lechuza.
I got most of mine from Amazon as I have towers made of Cascada & Cascadino pots joined together with a separate kit so each tower holds about 34 plants in a very small footprint.
I had to phone Lechuza to get the bases & I don't know if they still make the towers (you can get the other bits from Amazon, the pots & the joining kit for multiple Cascadas) because they only seem to be on the US site.
I also have a few of their windowsill sized self watering pots for herbs etc.. & hanging self watering baskets for strawberries & blackberries (Unwins/Marshalls who are the same company really.. is where I got the hanging basket blackberries from. Any strawberry can grow in a hanging basket but you must not forget to water them)
Other expensive kit I get from Greenhouse Sensation.
I have a number of their Quadgrows, Chilligrows, etc... in various iterations (designs have changed a bit over the years) some of which I've modded.
I also get my grow lights from them as I have Vitopods but I bought all this stuff over years & get given bits for Christmas/Birthdays etc...
I use the greenhouse layers to get early starts on most things & with the grow lights you don't get leggy plants.
I think I got my fruit cages from them too.
The only thing I ALWAYS get from there is their Nutrigrow plant food.
I get consistently better harvests using it & everything that uses regular plant food loves it.
You need different plant food for blueberries etc... which I just normally get from whoever has it cheaper - usually a supermarket or Wilko in the summer.
You don't need all that kit though, you can just get a couple of buckets literally & grow most things in those.
You don't even need self watering pots although I like being able to forget about them for a week or two at a time & find everything still happily growing.
You can also make much cheaper versions yourself that do the same thing.
I did buy some cheaper ones in Wilko.
They were okay but have tiny reservoirs & you have to refill them by watering the soil plus if you overfill they just flood all over the place (more expensive ones the plants have to draw the water up through your growing mediums which encourages deeper roots & they have gauges or you can see how much water you put in)
For cheap & cheerful but with brilliant results look up this guy
www.youtube.com/channel/UCPrZIwOWNvem_IAuGgmIWlg
He's (& his dog Molly) awesome & I personally find him extremely amusing at the same time as very informative.
I learned to sow carrots using a grid to space them out from his channel.
It's really effective.
I find Wilko pretty good value for a lot of things but they are rubbish for garden net or fleece sort of stuff so I tend to get that from Amazon.
For seeds I look for heritage seed companies.
Some sell things others don't so it depends what I'm looking for.
When I started this current garden ten years ago I was so brassic I just purchased seeds in Wilko as they are very cheap.
They grew really tasty food.
Most fruit bushes I've blagged cuttings from other people over the years if the fruit tasted fantastic.
I pretty much just look for small companies who are passionate about what they do & garden themselves if I can afford to do so at the time or if it's something a little more obscure like Skirret.
If I'm broke & I have no seeds, I'll just go where they are cheapest.
I think it's planting in the right medium & actually giving them plant food (don't use plant food on stuff in compost for first 8 weeks or so as there is some already mixed in) that makes the difference.
If you have self watering pots, put the plant food in the water don't water the plant with it.
I don't use pesticides in general although I do buy nemotodes to get rid of the slugs.
I usually buy them from gardeningnaturally.com
I should point out I'm not a casual prepper or gardener though.
We live on this food so if I can, I invest in top notch equipment if it makes it easier to produce better harvests.