As for steel structure steel, how appropriate
The size of the material is strongly related to the load on your floor, and the roof material and column size are also related to your span and the local Blizzard loads. You can choose the size of the material according to the local conditions.
Column: 200*200*8 rectangular tube as column, beam (main beam) is 300*300*12, secondary beam is 150*150*8@1500 evenly distributed. Roof beam 150*150*8 herringbone roof truss.
