Hello!
So I think the 'Copying a spell into the book' section in the general wizard class page is out of date. Recent published PHB and also on D&D Beyond have the text as:
"When you find a wizard spell of 1st level or higher, you can add it to your spellbook if it is of a spell level you can prepare and if you can spare the time to decipher and copy it."
Currently, I think the version on this wiki is the original print where it says:
"When you find a wizard spell of 1st level or higher, you can add it to your spellbook if it is of a level for which you have spell slots and if you can spare the time to decipher and copy it."
Usually doesn't matter for a single class wizard but it wreaks havoc when there's a 1+ Spellcaster / Lvl 1 Wizard multiclass haha