No such thing as auto flower soil.
Soil is complicated but the thing you want to know is how hot/rich is it? We can tell this by using a tds meter.
You can make your own mix with some compost, some coco or peat, and perlite.
Many many brands out there buy a bunch of local brands and do a tds sample. Find the one you like the most that is nice and rich, add 30% perlite or vermiculite and find a lighter soil to start your plants for the first week or two.
I recommend coco over soil.
Unless your in large large pots you will be feeding nutrients anyways, and your yeilds with coco is double or more.
In a 5 gallon pot with the best soil you’ll get about 4 weeks maybe 5 before you need to start feeding nutrients anyways.
Feeding with coco is much easier as well, with soil you have to do math on every plant individually and find out whats left in the soil before you feed or you could over feed and torch the plant.
With coco you can just feed them all the same and much less math.
Soils less investment up front but you’ll need to invest in nutrients eventually.
Watering plants is also a fair amount of work because you need to water, clean up run off, test it, etc.
That’s why I recommend autopots and coco.
Feed everyone the same feed, no run off, fill up a tank once a week and good to go.
Also much better on the environment due to no waste. Also bigger yeilds.
Check out my guide.