As a young carpenter, that wants to be an old carpenter, my go to is-
If it's dusty, wear a mask. Particularly with anything that is rot resistant(Cedar, yew, tropical hardwoods, etc.) PT and cement fiberboard require a proper mask.
If it smells bad, wear a respirator. VOCs will make you sick quick. The lower VOC products can by used in well ventilated areas pretty safely.
Wear gloves when finishing, your skin is the biggest organ, and touching your face, going to the bathroom, etc can spread whatever you're working with. Same goes with PT lumber.
Most wood/hide glues are pretty innocuous, but the other stuff they put in osb/ply is there because it kills things. Epoxy and other synthetics may require a respirator.
Keep it safe and keep cutting!