I've just started Playing D&D and the DM has given me inaccurate information so I need some clarification. My character is a Cleric with Wisdom 19 and follows the Trickster domain. My spellcasting modifier I think is calculated by using my proficiency bonus plus my Wisdom modifier plus the spell level. Which I think means, when casting a level 1 spell, I add +4 to it.
I'm trying to help my friend and he's playing as a wizard. Assuming what is above is accurate, does he just swaps out wisdom for intelligence, and that's how he determines his spellcasting modifier?