Actually, it really depends.
Don't forget, photoshop is a generic term that can mean PHYSICAL photo shops. Also, if it is against Adobe's trademark, websites such photoshopessentials.com, elearnphotoshop.com, and many more would have long gone. There are many domain names that include "photoshop". Note how most of them insert a disclaimer at the footer of the page, and they don't use any of the logos from Adobe.
UNLESS if you're using Adobe's and its photoshop logo, which confuses visitors thinking it is a legitimate website by Adobe, then you're in trouble. Or if you're using it in bad faith.
If you're really just putting up lessons on how to use photoshop with google ads and such, then it 'should' be okay.
But then again, why risk it and go through all the trouble to avoid legal complications?