Here’s a quick read (which you may already have seen) from Bob Vila’s web site. It’s focused on safety and durability, and some materials to avoid. (Compressed concrete blocks, for example, are on a list of materials not to use because they can trap steam and eventually explode.)
If you are building a raised structure, you can use standard concrete blocks and apply a decorative veneer to them. If you are concerned about heat damage, it would be fine to use the high-temp mortar recipe for those blocks, but I don’t think it will add much to your build.
The big difference between a fire pit and a wood-fired oven is that the fire pit radiates most of its heat immediately. Infrared energy warms the inner walls, and the pit itself will absorb heat from direct contact with the fuel. The oven is designed to retain and concentrate heat energy rather than radiating it. It has to withstand much higher temperatures, and ideally it would do that indefinitely. Ordinary brick and concrete would deteriorate and crumble through the heating and cooling cycles of an oven, so that’s why the firebrick and special mortar are used.
I do wish you the very best with your project, and hope you’ll let us know how it turned out!