In my experience, running a small business has nothing to do with certifications, and everything to do with personality, and productivity... You gotta make life easier/better for other people. At the farmer's market nobody has ever asked me about my training in plant breeding or farming. The results are sitting right there on the table between us. Their taste buds are the only certification that's required.
I think that the education system of the world has failed... Certifications these days seem to be mostly about whether or not someone paid the required fees, not about what they learned. And especially they don't seem to be about a person's ability to actually do productive work in the real world.
So if it were me, and I had my life to do over again... I would seek out the shaman, and the medicine women, and the farmer's and gardeners that are making a living doing what you want to learn, and
volunteer. There are frost emergencies, and spring planting, and summer weeding and fall gleaning, that always need to be done. They are part of the ongoing burden that growers face. Stop by and help out... Be about working and not about talking. I cringe when people want to come and help me, because they slow me down, and the total work output while they are there is less than what would have been accomplished if I was working alone. So be one of those rare individuals that produces more than you cost and you'd be welcomed to any farmer's fields, or any medicine woman's foraging trip.
For the cost of a formal training program, you could travel the world, and learn directly from the who's who of the fields that you are interested in. You could spend a summer in Hopiland, and a week at the Rocky Mountain Seed Alliance training program. You could sit at the feet of
Sepp Holzer, Paul Wheaton,
Geoff Lawton, Vladimir Megre, Susun Weed, etc.
Then put what you learned to good use... I suspect that with 5 to 8 years of good hard work, that you could position yourself to be one of those "must visit" destinations for anyone interested in your field of study.