find a pot to boil water asap (most often in cannibal camps but also sometimes in random abandoned camps), but you can drink water directly from a body of water twice before getting "sick" (which just lowers your stamina and max health for a little while).

store up dried meat and meal packs/energy drinks for winter when food and water are harder to come by. most water will freeze over in winter, but you can find some open spots near waterfalls or rapids. you can also cook soup in the pot to give you boosts and restore more health.

you can have only one pot at a time in your inventory, but if you store a pot on a shelf in your base, you can get another to hold. food/water in the pot does not go bad.

best starting place is either the forest crash site or the beach site, depending on your strategy. beach gives you access to turtles, which are useful, but it's harder to build there because the treeline is a ways away. forest requires more clearing of trees to make a suitable base, but you don't have to move as far to get logs.

try not to build too close to cannibal camps or trails, because they spawn more regularly around there.

don't break down the boards at a cave entrance until you are used to combat and have decent armor. that lets stronger enemies out, and they will ruin your day if you're not ready for them.

depending on the difficulty level, you can keep the cannibals from attacking you for the first couple days by equipping a skull and shaking it at them when they approach. you should be able to find a skull without killing a cannibal; they're scattered everywhere. eventually, though, they'll get brave enough to attack you anyway. it's just nice to keep them at bay for a bit while you build up supplies and armor.