First-time cat owner essentials — what do you actually need?

For when we finally get our Maine Coon (manifesting this into reality), I've been making a shopping list. But honestly there's so much stuff out there — what do you ACTUALLY need vs. what's just marketing? What I have on my list so far: - Quality food (wet and dry) - Litter box (how many for one cat?) - Scratching post (tall one for a MC?) - Carrier - Basic grooming stuff What am I missing? What did you buy that was a waste of money? What was the one thing you didn't buy that you wish you had? Tips for Maine Coons specifically would be amazing but all advice welcome!