Any Wizard worth their Weave wants to learn as many spells as possible. When you begin your journey in Baldur's Gate 3, you'll spend a lot of time scouring each map for scrolls to learn. At each wizard level up, you can select two spells from a long list that your wizard can learn on their own.
Baldur's Gate 3: How to Get & Learn Secret Spells Artistry Of War & Dethrone
Some spells can only be learned by finding special scrolls holding hidden knowledge.