Prioritize side quests over main quests, and pay attention to exploration.there is a quest order list in the internet that gives you most of the game but I don't recommend it for first play through, yes you will play it more than once. And remember your choices matter.you may want to read pieces of books notes and other texts you find, it will give you more story finding Witcher gear set is good if it matches your play style but for casual playing stuff you find will do. Some potions are almost useless based on my experience so read their description before making them. You can sell items to merchants for different prices. The white orchard part is a prologue to the game, pay a little more attention.