To learn the style:
1. Find as many pages and strips as you can from artists with this style (like Alex Toth, Milton Caniff, Wally Wood, David Mazzucchelli, Eduardo Risso, Chris Samnee, Tonci Zonjic, Goran Parlov, etc.), print the art enlarged and in light blue, ink the shit out of them.
2. Start making a collection of good frames from movies and tv series. And try to recreate them with ink in this style. This is good practice also because you will build a reference library, and in comics you have to draw a lot of different shit.
While you're doing this you can also train your fundamentals with other books and such, depending on you skill level. These are the ones that I found be more useful:
Loomis Figure Drawing for All It's Worth and Atlas of Human Anatomy for the Artist. Self explanatory.
Perspective for comic book artists. Best book to understand the principles of perspective without being too autistic. Keep in mind that a lot of the time you will not build grids, vanish points, etc. The main tool you will use will be the horizon line.
Making Comics. Helpful to learn some general rules about comic book storytelling.
Framed Ink. This one is about composition.
The Art of Comic Book inking. Really good book on inking.
You can find them in the artbook thread or on libgen.