GLFS stands as a format in between LFS and BLFS so this part is crucial to understanding what you need to read and/or follow in order to get out of the system that you desire. For starters, LFS is meant to be followed in a linear manner, whereas BLFS handles things by putting related packages in the sections they are best described as categorically. For example, printer software being in a printer section, although most packages can be discarded by the user.
As previously mentioned, GLFS stands as a format in between the two books. Not every chapter will be necessary but depending on what the user wants will have to read everything in the relevant chapter depending on if they desire to go with multilib or not, which is discussed in the multilib chapter.
By default, every user should read the multilib chapter as most users that want Steam and/or Wine should have a x86_64 CPU capable of 32-bit emulation. If that chapter is skipped, it might be realized to be a mistake and would cause a headache at the final stages.
The following chapter is Shared Dependencies. Every user who wants Steam and/or Wine will want to read this chapter as both projects use the packages. Try as you may, but this chapter is absolutely necessary. However, it is recommended to check the dependency lists of Steam and Wine to see what exactly you need from that section instead of installing everything despite only needing maybe 90% of it.
The next chapter is Steam, which covers all the packages, patches, configuration, and setup necessary to get Steam working and capable of the playing the following: Linux games, Windows games via Proton, and games using OpenGL, Vulkan, and Direct3D. It covers both regular compilation of packages and lib32 compilation of some of the same packages. If you read the multilib section and decided that you desire NOT to go with multilib (despite any warnings), you can ignore the lib32 variants of packages). Otherwise, follow every step unless told otherwise in the respective sections or are presented with options.
The following chapter that most users will need is Wine. Likewise with the Steam chapter, users should follow every step in this chapter if they want to install Wine and use it. The Wine chapter at the moment does not consider retrofitting and will handle it in a similar manner to Arch: get toolchains, install audio and video components, then finally Wine itself. This chapter will depend on packages listed in the Shared Dependencies section, so when prompted, go to the package it lists, then go back. This is done to avoid duplicate sections.
The last chapter covers quality of life improvements and packages. This chapter is not required but recommended.
We hope you enjoy using GLFS. May you realize that LFS can provide you of your gaming needs!