Carter Cutlery used to have some good YouTube vids in stone sharpening. Something like that is a good place to get some first principles. Then I would honestly watch a bunch of Japanese guys maintaining their kitchen knives.
I used to have a couple vids of an American guy that spent ten years at school in Japan, who loved knives. Spent a bunch of time learning water stone work from sushi chefs and some bladesmiths. I can't find them now, but I will see if I saved them to my drive when I can.
Get the basic use and principles from a reputable source like a Knifemaker or one of the good cutlery vendors mentioned above. Then watch the movements of people that do this as part of their profession, like master butchers or sushi chefs, to get a better idea on refining technique.
I use a block designed to hold different sand papers specifically for knife sharpening. Mostly I use it as a variable grit stropping instrument. If you strop your steel every few days or every week, you rarely need to sharpen unless something bad happens. You could easily build a DIY leather strop out of some scrap leather, tacked to a wood block, that you apply some polishing compound to. Green rouge is a good general purpose for most steels. You can get a bit at any hardware store where the buffers or grinders are.