The wizard spell list is extensive and there’s no perfect choice. Pick a good damaging cantrip like Fire Bolt, utility options like Prestidigitation and Mage Hand. Great 1st level spells include Absorb Elements and Shield to mitigate damage, Magic Missile for automatic damage, Feather Fall so you don’t fall to your death, Find Familiar to scout and gain advantage on attacks, and Alarm so your party doesn’t get ambushed when resting.