If you're smart and common-sense oriented (and either a beginning or fully initiated Christian) you will likely have concluded, after studying all the basic areas of higher influences (art, music, history, imaginative literature, philosophy, science, religion) that philosophy is a lot of gobbledeegook. Mental masturbation by people who can't accept Christianity, or refuse to, and who put way too much confidence in the powers of their intellect, or any human intellect. You see it as too surfacy as well. Not deep. Surface knowledge as opposed to deep language. And you're right. Worldly type philosophy, it should be said, can be more practical and useful. Carl von Clausewitz' On War, Adam Smith's Wealth of Nations, good political philosophy based on biblical anthropology, Montesquieu's Spirit of Laws, for instance. These works are hardly a waste of time. But analytical philosophy; or the big system building philosophers associated with the European continent, and anything similar seems - or can be - ultimately empty, often silly, sometimes evil, overall shallow in contradistinction to Biblical wisdom. (Caveats would be practical handbooks on aesthetics like Edmund Burke's little book on the Sublime and Beautiful, etc.)
After that preface here are three things to know to help one get a basic sense of the field of learning called philosophy nevertheless:
1. I read this in some book by R. C. Sproul, and it stuck with me: all philosophy takes place between two poles: one pole is Theism; the other pole is Nihilism. I.e. these are really the only two honest positions. Everything that happens in between these two poles is 'philosophy.' Nietzsche, for instance, is called a rare honest atheist because he admitted he was a nihilist. He embraced that pole of the spectrum. He conceded that was where he stood because he stated that he would rather believe everything was meaningless and absurd rather than believe in God. (This brings up the question, can you learn anything of worth from a philosopher who is not a theist, like Nietzsche? Yes, with Nietzsche, for instance, you can learn a lot about honesty. Nietzsche is good on that subject, even if just in an indirect way. I picked up on this when before I was a Christian and read a lot of Nietzsche. His remarks about Thucydides, for instance, brought this subject out. Nietzsche, as a general writer and thinker, can also be bracing in a real way. For instance bracing in going against the easy currents of the world. Ironically this is what a Christian ultimately does, or should be doing, when a Christian fears God alone and does not fear the world or the world's opinion of the Christian, etc.)
2. A practical and powerful way to learn about philosophical schools and ideas is through the discipline of worldview analysis. Philosophers hate worldview analysis. Why? Because it brings down their strongholds and does it rather easily. It tests their assumptions and consistency and rather deftly exposes them as wanting. How does worldview analysis do this? It does this by coming at philosophy from the base of biblical revelation and wisdom. A good book on worldview analysis would be whatever the latest edition is of James Sire's The Universe Next Door. David Naugle's Worldview: The History of a Concept is a good, more academic-oriented overview. Anything by Nancy Pearcey is worth reading as well. (The Naugle book will direct you to other very good books on worldview analysis from the turn of the 20th century up through until today.) There are also websites that will define the basic worldviews in a concise way. Just Google worldviews.
3. A third thing to know about philosophy to have it in perspective is how ideas - especially bad ideas - have a really kind of supernatural ability to speedily infect large populations of people and define whole eras of human history (think Marxism). This is because it is part of Satan's power in this realm (one of the things in his toolbox) to control people. Satan is the prince of the power of the air. David Naugle speculates convincingly that this includes Satan's ability to control what ideas get propagated through the 'air' (the universe of discourse), hence it being mostly bad ideas that get the supernatural ability to take over quickly in the minds of average people, and not just the most hollow and shallow among us. Related to this is another of Satan's great advantages in doing battle with the human race: the fact that each generation is born a blank slate to a good degree. This is how a country can be inflicted with a Satanic ideology that results is widespread suffering and even genocide and then the very next generation can be born and fall for the very same ideology because they are blank slates. This is why civilization relies so heavily on inter-generational educational efforts, and traditions, and ritual and so on to keep the light of truth and wisdom going generation to generation. Satan's children for this reason always infiltrate and destroy educational establishments and institutions. The left in America did this and has completely destroyed education from Kindergarten to the Ivy League. Anyway...