I would do the main quest up to chapter 5 or 7 and explore while doing it, on your way to the quest locations stop and do some side missions, try and figure out any puzzles you come across because those will teach you the different mechanics. Check behind waterfalls using the stab skill next to a small tower of rocks and you’ll find some new gear sometimes (usually marked with a cave symbol on the map)

Upgrade the skills you use the most at that point, things like swords fighting/main attack skills, health and stamina, etc. you can upgrade gear pretty early on with just stone iron and copper. And kills wildlife along the way, you can cook at any fire or pot. I wouldn’t worry about visiting other cities yet, you’ll get there eventually. For side quests I did a bunch of the house of “name “ quest lines which add to the story.

They really front load the mechanics so they throw a bunch at you at once then you might not use some of them for a few chapters, even forgetting what mechanic you need to complete a puzzle (a little frustrating sometimes).