How do I make different parts on the same page?

Sounds like exactly what I said, then. In which case, not so different really, it’s just a whole bunch of instruments half of which happen to be playing the same music. Just add each of the instruments you want = two clarinets, two horns, two violins, etc. And use the up/down buttons in the instruments dialog to organize them into those two groups. You can add brackets from the palette to identify the different groupings. Only thing that is a little awkward is adding the names for the groups, you’d have to add staff text and position it manually if that’s important to show. Probably just on the first system.