Survival the majority of the time.
DMG pg 111 - Foraging
Characters can gather food and water as the party travels at a normal or slow pace. A foraging character makes a Wisdom (Survival) check whenever you call for it, with the DC determined by the abundance of food and water in the region.
Foraging DCs
Food and Water Availability | DC |
---|
Abundant food and water sources | 10 |
Limited food and water sources | 15 |
Very little, if any, food and water sources | 20 |
If multiple characters forage, each character makes a separate check. A foraging character finds nothing on a failed check. On a successful check, roll 1d6 + the character's Wisdom modifier to determine how much food (in pounds) the character finds, then repeat the roll for water (in gallons).
The food and water requirements noted in the Player's Handbook are for characters. Horses and other creatures require different quantities of food and water per day based on their size. Water needs are doubled if the weather is hot.
DMG pg 111 - Becoming Lost
Unless they are following a path, or something like it, adventurers traveling in the wilderness run the risk of becoming lost. The party's navigator makes a Wisdom (Survival) check when you decide it's appropriate, against a DC determined by the prevailing terrain, as shown on the Wilderness Navigation table. If the party is moving at a slow pace, the navigator gains a +5 bonus to the check, and a fast pace imposes a -5 penalty. If the party has an accurate map of the region or can see the sun or stars, the navigator has advantage on the check.
If the Wisdom (Survival) check succeeds, the party travels in the desired direction without becoming lost. If the check fails, the party inadvertently travels in the wrong direction and becomes lost. The party's navigator can repeat the check after the party spends 1d6 hours trying to get back on course.
Wilderness Navigation
Terrain | DC |
---|
Forest, jungle, swamp, mountains, or open sea with overcast skies and no land in sight | 15 |
Arctic, desert, hills, or open sea with clear skies and no land in sight | 10 |
Grassland, meadow, farmland | 5 |
So, that answers what the check is, what success means, what failure means, whether or not you can get lost, how much food you get when you hunt, and how difficult the checks are.
Literally every question you had was already answered by the game.