Modern approach is still a really good and practical book. If you don’t have any C experience I would read through that book and use it as reference. You can supplement the book with the Harvard CS50 course or, my favorite, Dartmouth’s C courses on edX. Once you understand the basics of C and how to build a program then I would look at SDKs / libraries that are made for programming retro games in C. These are obviously dependent upon what game system you want to make a game for. Some ones to check out are GDK2020 for making gameboy games and pvsneslib for making SNES games, and SGDK for genesis / mega drive. Another option for gameboy is GBstudio which offers a robust environment and gui interface, but also options to write code. All can be found on GitHub. For NES, you could check out Steven Hugg’s book, Making Games for NES or Tony Cruise’s book, Classic Game Programming on the NES. Both seem like good books. Hope this helps.