Hi Dogslife,
I can certainly understand the “overwhelm” in the environment that most people are exposed to in their mattress shopping.
What I usually try to do is to “decode” the more commonly used terms like “medium firm” and relate them to the basic functions of a mattress which are pressure relief and spinal alignment. “Medium soft” … depending on who is using the term … can relate to the top layers of a mattress (the comfort layers), the lower layers (the support layers), or the “overall feel” of a mattress. Each of these different meanings would “translate” into a very different mattress.
I would start by reading this The basic functions of a mattress - Overview - The Mattress Underground which is the best place to begin.
If you can let me know your height/weight and body shape and your normal sleeping positions it would help me to make a few more specific recommendations for what may work best for you. If you also let me know the city you live in, I would also be happy to look and see if there are any factory direct mattress manufacturers or outlets I know of that are near you. These are usually where mot helpful people, the best information, and the highest quality and best value mattresses can be found.
In reply #6 here https://forum.mattressunderground.com/t/latex-mattress there are some guidelines that should also help you avoid most of the traps that you will encounter in your mattress shopping.
Of course you are always free to ask any questions here about specific mattresses, your own field testing, or what may work best for you along the way 
Phoenix