It's not really that bad. There's a lot of pictures 😌
My study method was a chapter at a time, for the questions at the end of each chapter I made sure I could answer them without resorting to looking at the back of the book. I did the questions over and over until I could.
Its heavily focused on text files unfortunately, which isn't something I dealt with at work, since we work off servers.
Make a a schedule and stick to it. Decide how long you need per chapter, and multiply that by the number of chapters. Some will be easier and some are harder but the Base Certification is not difficult if you work with SAS on a daily basis. And by that I mean writing code, not just running scripts.
Good Luck!