I remember seeing and taking out "Theory of Wing Sections" from our bigger main library many years ago. It was more to try to pick up on some sort of general understanding rather than hack through the math. For that purpose there were about 15 to 20 pages that helped. From there it was full on jumping into the deep end armed with a slide ruler. Yes it was THAT long ago. I was a teenager without the math knowledge to understand more than a tiny handful of the math.

If you go that deep into this I'd also recomend tempering what it teaches with reading the prep work that Michel Selig did in getting ready for his first big wind tunnel work. There is a lot of good information in there about the differences in airfoil shapes for lower reynolds numbers such as we use. That transition may also help you to understand why for super low speed airfoils such as free flight and indoor that the airfoils of choice get increasingly thinner and why an arced flat plate is the best choice for extreme and stupidly slow flight.

It's also interesting to see the shift away from mathematically designed airfoils such as the NACA stuff and the use of pressure distribution analysis as used in Xfoil where the shape means little as long as it provides a suitable pressure distribution.