The most important things are at the very top, the ones you’ll find most useful and to which you would regularly refer.
Unfortunately, Personal Philosophies now is useful for most people.
Process Control and Technique Discussions are important when you develop new plans and policies, or evaluate those of others.
If you want to do or to understand policy, you would find one or more of the Government sections interesting. They still are worth a skim as an ordinary citizen – there are some important macro concepts in there.
Explanations will be useful in reading and discussing with other people, as you likely will improve your technique.
If you don’t have a background in philosophy, you should suffer through the Metaphysics section at the bottom and keep going from there. It’s painful, but necessary, training.
You should understand the content in the utility/happiness sections. Some of it you may be able to skim through, but not knowing that will get you a lot of hard knocks, and will make it more difficult to understand the most important content. This is what is most important about “philosophy” – being able to say what the “good life” is and how to live it. The https://aplanthatcan.work Personal Plans content continues along these lines, although from a more prescriptive point of view.
If anything in Various Opinions is relevant or interesting to you, read it. Not all are necessary for your life.