It's so dense. There's so many things to build, so many ovens, and I never seem to have any of the materials. I hope in future versions the game will be able to sort the modules page by things like "ovens" and "furnaces" in order of quality. I have a very hard time navigating that page to find the starting modules.
Allow me to explain The function of the metalworks is to: a) turn raw ore (e.g. hematite ore) into ingots (i.e. iron ingots), ready for use in manufacturing b) manufacture products (e.g. pistols) and modules (e.g. Vacuum Chamber, Mechanical Brewing Vat) that incorporate extensive use of metal Prerequisite: a Ceramics Workshop with a workbench. Start by building a (1) Stone Smelting Crucible or two. These are the modules used to smelt ore into ingots. Stone Smelting Crucibles are produced at a workbench in a Ceramics Workshop. Build a (2) Workbench in the Metalsmith. Workbenches are manufactured at the Carpentry. This module is necessary to build many things in the Metalsmith, and is needed to Build a (3) Smithing Forge, which is assembled at the Metalsmith's Workbench, using refined Iron Ingots and Bricks. Those are the crucial first three steps. Everything else the Metalsmith produces requires ore from (1) the Smelting Crucible, and is assembled at either (2) the Workbench, or (3) the Forge. Modules (4), (5), and (6) are really just upgraded versions of existing modules, so get around to those only when you have the resources to spare (and they require finished metal components in their construction). A note on coal / charcoal: to smelt any ore into an ingot, you must also have one unit of fuel, in the form of either coal or charcoal. If you've been mining, you'll be digging up a small amount of incidental coal. The two charcoal kilns aren't necessary until you need a steady stream of fuel, and building them will allow your Metalworks to turn timber into charcoal (which can then be used in the smelters).
The Smithing Forge is constructed at the Metalworks. It requires that you have a workbench, some brick, and a couple of iron ingots. Do you have all of those? (You have to both queue it up for production at the Metalworks, and you also have to place the module from the module list.)
I don't know. I should have the iron ingots but it is hard to check. The place won't make much of anything despite tons of material lying around (my mine does not use their stockpile). People have stopped mining rocks, I don't know why. You'd think with 60+ people someone would be free to mine rocks or set up a new bed. And I have no idea what that yellow rock is at the Chem Lab that almost every item needs to be built.
I don't know what's causing your metalsmith problems, but that yellow rock is sulphur, which can be mined from surface and subterranean deposits the usual way.
Ah, sounds like you need to make a Smelter (Stone Smelting Crucible, at the Ceramics workshop) and then in the Metalworks use Smelt Iron to turn your iron ore (hematite) and coal into Iron ingots. See this post in: Building Buildings (and Modules) Open your commodities list (top left, it's the little stockpile icon) to see what your colony has. Give us a screenshot of that open which also shows your colony