Should i cease the pursit of earthly achievments? Should I cease the pursit of earthly achievements?
No. Get back to work.
That's it in a nutshell, but you might like the expanded version.
First, stop reading pessimistic philosophy, at least until you are 60 years old. Now is the time for you to embrace the world, engage fully in life, and flourish. When you get older you will have plenty of time to poke around the sub-basement of Philosophy's House of Horrors.
Without a good education (in something useful) your chances of having a job that pays enough to travel around the world, making friends, getting laid, seeing the sights, trying new foods, etc. are slim to nonexistent.
Is the world meaningless, pointless, fleeting, temporary, and transient?
Well... sure. The material world without life and intelligence is kind of pointless, meaningless, dreary. But... with life and intelligence the possibilities of meaning and purpose are extensive. Our lives do not last very long -- 80 years out of 13 billion years is not even a flash in the pan, but that's what we get. The history of civilization is not very long either -- 5,000 years, give or take 15 minutes. Not a long time, but it is our time, our place, and our task to make the most of it.
The world, your life, your legacy will be as meaningful as you make it. This is true for everybody. And because most people do engage, embrace, and enter their lives fully, life is good.
And remember: You are a teenager. Teenagers quite often have a lot of sturm and drang in their lives just because their brains are not actually fully formed yet. Depending on your age, your body isn't quite finished either. You want to get on with living your life, but you can't yet. Very frustrating. Life gets better as you get older, in most respects. (In some respects it gets worse, but uplift is my purpose here, so we'll not go into all that.)
Study hard, pay attention, learn a lot. Find a good career and pursue it. Read widely in the arts and sciences, but avoid those fucked up life-is-meaningless pessimistic philosopher pricks -- no Schopenhauer for you for 40 more years, at least). And do get laid regularly.