Not required, but knowing a little relational algebra helps queries make a lot more sense. A lot of the features like constraints and indices are very thin veneer over the underlying concepts.
At the other end of the spectrum, once you can write a few basic queries check out something like SQL Murder Mystery https://mystery.knightlab.com/
This one is super-fun and lets you practice some basic to low-intermediate skills.
I will echo what others have said. Data modeling is a force-multiplier type of skill. Combine it with a reasonable understanding of SQL and you can return a lot of value very quickly.
[1] https://www.amazon.com/Database-Design-Mere-Mortals-Hands/dp...