Hunger: Raised by eating food
Thirst: Raised by drinking
Tiredness: Raised by sleeping
Method 1: Slaughtering an animal
Step 1: Find an animal. Wander around and look for an animal. Every month save generates new animals if there's a scarcity.
Step 2: Once you find an animal, right click and slaughter it. This shoulder yield raw food components. Do not eat them raw, they're much more satiating when you cook them.
Step 3: Find a tree, use the collect wood verb until you have enough wood for a campfire, start a campfire, cook the food and eat it.
Method 2: Growing crops
This method is a bit more advanced, and will be covered in its own guide.
The guide can be located here: https://www.byond.com/forum/post/2841931
Method 1: Creating a water purifier
Step 1: To create a water purifier, you're going to 35 Stone, 25 Copper, 35 Coal and 25 Titanium. To acquire aforementioned minerals, just start using the mine verb. Keep mining in different areas until you find the minerals you need. Make sure you extract all the minerals in that specific spot before moving to another tile.
Step 2: Once you have enough minerals for a water purifier, you need to collect sea water. Walk around until you find any mass of land water, stand adjacent to it and begin collecting sea water. Collect 10 to 30 bottles.
Step 3: Once you have sea water, build your purifier (make sure you toggle Build Technology). Right click the purifier, and begin purifying water. After some time, the water will be purified. Right click and collect it.
Step 4: Drink the water.
Method 2: Finding a cow (Planet Earth only)
Step 1: Wander around until you find a cow. There are quite a few on Earth. Only on Earth.
Step 2: Right click and harvest. If the Cow has not been harvested recently, you will acquire some milk. Otherwise, you will have to wait a short while before harvesting the cow again.
Step 3: Drink milk.
Method 1: Creating a bedroll
Step 1: To create a Bedroll, you're going to need 500 Stone, 500 Copper and 500 Titanium. Make sure you toggle Build Technology.
Step 2: Mine the required minerals for it.
Step 3: Build, or get the Bedroll built for you.
Step 4: Place the bedroll down and sleep on it until your tiredness has reached the maximum 100%. Make sure you don't lose your bedroll, you're going to need it.
Method 2: Bed
An alternative option is to build a Bed. This method is much harder and requires a good amount of Zenni.
Step 1: Collect enough Zenni to build some land. Toggle the Build verb (different from Build Technology).
Step 2: Build some land, using the Build tab. You really only need a couple tiles of space for the bed.
Step 3: Build the bed on your owned land.
Note: This method is expensive early on. If you do not have enough Zenni, you're going to need to cooperate with other players.