Craft armor as soon as possible. You don’t want to be constantly running back to your death location to pick up your loot. After you craft your axe, it won’t take too long to farm up some wood to get at least a full set of wooden armor. If you are low on health, take advantage of your companion and let it do the damage while you heal up.
When attacking (or being attacked by) multiple enemies, try to focus on one at a time. It is quite hard to fight more than two enemies at once, because most of the time you’ll constantly be doing the attacking instead of having time to deal damage. Take advantage of the throwable wrench to stun and deal damage to a target.
You can get a pickaxe schematic from Burl. He gives you a mission to return to his house and clear out some wompits.
To regain health, keep an eye out for plants that can be eaten. Items have a cooldown when consumed/used but they regen your health over time. Wander around the map to look for villages. If you talk to the locals they’ll give you more quests, unlocking more schematics for crafting.
Take a little time to just farm materials. When you collect key amounts of materials JuiceBox will give you schematics. You can find stones around the map that give you temporary boosts when you tap on them. Keep in mind they have fairly long recharge timers.
It’s good to keep ranged weapons like sticky bombs on you at all times. It’ll make taking on bigger enemies easier so you don’t have to risk your health, especially if you are far away from a teleport location. Plant as many baconweed plants as you can at your home. It only takes 20 minutes for them to refill. If you have the patience, you could farm off the plant and replant them to get even more. You could leave your phone on while doing something else.