How can I determine which items I can safely sell?

I've never played a Monster Hunter game before so I'm going through the various tutorials, venturing out into Moga Woods for each quest with little to no idea what I'm doing. In the meantime, I'm also gathering stuff from nodes obsessively because that's what I do in games. In addition, I receive Commodities when I turn in Resources in the Village.

Rarity doesn't seem like a good measure, as I have a Rare 4 item (Velvety Hide) whose description says "the going price is low" and a Rare 5 item (Pittance Fang) which also says to just "sell it for pocket change".

I figure many of the items I receive can eventually be used in Combinations I don't have unlocked yet, or maybe upgrades/crafting, so it's hard to know what things I can sell safely, if any. The only things I've felt safe selling are Garbage and Burnt Meat (despite the descriptions of the rarer items, I still haven't sold them yet). How do I know which items I can safely sell? Or is this one if those games where nearly everything is used for something, so I should just hang onto all of it?