Calculating Wizard spell casting ability and spell attack bonus
Page 114 of the player's handbook under the Spellcasting Ability header lists the ability and relevant spell modifiers for wizards:
Intelligence is your spellcasting ability for your wizard spells...You use your intelligence whenever a spell refers to your spellcasting ability:
Spell save DC = 8 + your proficiency bonus + your Intelligence modifier
Spell attack modifier = your proficiency bonus + your Intelligence modifier
Note that the same rules can be found on page 32 of the basic rules
Is the spell casting ability just intelligence, because I read somewhere just barely that it was intelligence minus 10 divided by 3
@VapeNation420 Your Intelligence Modifier is different from your Intelligence Score. This shouldn't be discussed in comments, so I'd recommend doing some additional research on that, either by asking another question, or reading more of the player's handbook.