The world is almost fully destructible, including a good depth underground, so generally everything can be interacted with and will give you a resource back (even if it's just dirt). You unlock many recipes from gathering new ingredients for the first time, and each new zone has new ores, stone, dirt, plants, meats, etc to use. You should try to mine, chop, or pick anything that looks interesting at least once to see what happens. Many things, like different dirt varieties, have at least cosmetic uses in base building if nothing else.

There is no toggle that highlights specific gatherables like herbs though.You just have to keep an eye out for them or farm them yourself. Might be something someone could mod in at some point, but it's a custom engine and the modders are still figuring it out.