I'm in Wisconsin and sent mine in to the UW Soil services. There's a small fee and it usually can take 4-6 weeks in a busy season, but it will give you a window of information on what your soils health is. You can get a probe usually for a returnable rental fee from your county extension office to aid in your sample. And also you need to pull a few samples from around the same garden.
My report was emailed to me and I was told if I had any questions to contact them or my local ag agent. Most was fairly explanatory for what was needed for amendments. I seem to recall they have a basic testing and then additional testing for things like sulphur or others. Each state or region has their own issues of things they test for so this will probably differ. But as you add things to the basic test your fee does increase.
Good luck!
