Don't rush for the first boss. The danger in the game world progresses each time you defeat one. Instead, take your time and build up. Establish a homestead and fortify it. Hunt the deer, boars, and necks and stockpile a food supply. Craft and upgrade gear. Practice your archery and blocking until you can reliably hit moving targets and you can reliably parry melee attacks.

Also, grab anything that isn't nailed down. Mushrooms, berries, stone, resin, wood, etc. all have their uses later on in the game and you'll need a lot of all. Building a storage shed or something and organizing your stockpile into chests isn't a terrible idea.

The black forest is super dangerous when you're first starting out, so just keep that in mind if you come across one.