TL;DR starting with a list of the data types before querying the data is putting the cart before the horse IMO.

It seems a bit like DuoLingo. You learn a random assortment of facts, rather than being exposed to what people are actually doing. I learned MySQL by example and this is far from it. I don't recommend learning about the schema or the data types first, unless you're just being shown a CREATE TABLE statement with just the types you need in order to go through a CRUD example (having you start with a table that already exists and do a SELECT query first is also good). Otherwise, like with DuoLingo, you'll likely get bored, unless the reward mechanism grabs you. (DuoLingo is fully gamified. This has a bunch of short steps so you can watch yourself progress through them.)