I don't know enough about blues either. I've hung out on-line with a number of very good blues musicians and have picked up (from them and elsewhere) a few "tips" and shortcuts for writing "blues". They may have been exaggerating, but they've told me there are no "wrong" notes playing blues.

From "theory" though I am aware that there are blues scales that are not Do Re Mi Fa So La Ti Do. And more than one of them. How those chords get built is beyond my knowledge. So is how they relate to "key". I've just been told to use a lot of Dominant 7ths and concentrate on the I, IV, and V. That's probably blues cheat-sheet for beginners. But when "they" told me this, I didn't know what they were talking about (except for the 7th chords).

BIAB 2021 Audiophile. Windows 10 64bit. Songwriter, lyricist, composer(?) loving all styles. Some pre-BIAB music from Farfetched Tangmo Band's first CD. https://alonetone.com/tangmo/playlists/close-to-the-ground