Much of your time spent playing Monster Hunter Stories 2: Wing of Ruin will be spent doing bounties and quests. You will need to find all manner of monsters and resources to get these finished. The rewards for doing so are a steady supply of essential items that will help you throughout the campaign.
Quests can be collected from the main quest board in the center of town, near your home. They can also be collected from random quest-giving NPCs all over the various maps. You can see them clearly as they will be marked with a blue exclamation point symbol.
Once the quests have been completed, you will need to hand them in. Unfortunately, you cannot do this from the menus, and will instead need to return to the quest board in Mahana Village to hand them in. Interact with the board, find the quest that will be marked as completed, and then hand it in from there.
After handing in the quest, players will be able to get the relevant rewards and add them to their inventory. If the players got the quest from an NPC, then they will need to return to that specific NPC to hand it in. The NPCs will wave at you and try to get you attention after you have fulfilled the quest requirements, making them easier to spot.