I am a high school student and I have a couple of questions I need to ask for a class survey. First, who is God? Second, how did the world begin? Third, what is your purpose on earth? Lastly, what will happen to you after you die? Thank you so much for your time.
First, who is God?
Although many Buddhists do believe in what we can call "spiritual" beings, some of whom might perhaps indeed be powerful and might therefore reasonably be called "gods", the idea that there is one supreme creator-being responsible for absolutely everything is held to be pretty much nonsense. It is riddled with logical contradictions. And of course, since there is so much suffering wherever we look, the idea that any powerful being who is in charge of this world is both extremely powerful and loving is impossible. If there is such a being, he or she would be very unpleasant. Since you give a capital letter to the word "God" I rather assume that that is what you might have in mind. Most Buddhists will tell you that this idea is an illusion.
Second, how did the world begin?
There are plenty of speculations about the pre-history of the Earth and the universe that we see, and not all Buddhist speculations along those lines agree with each other. Mostly they are based on traditional Indian ideas. They can be very beautiful, and can often be used for artistic, poetic or meditation purposes, but they do agree closely with the understanding we have now reached through scientific methods. This is not important to Buddhists, since it is held that the ultimate origins of the universe are A) lost in the mists of unthinkably long time, and B) not relevant to the purposes of human life.
Third, what is your purpose on earth?
Mine is to be as happy as possible, to make other beings as happy as possible, and if possible to achieve liberation from the chains of suffering. Other people may have other purposes - you would have to ask them.
Lastly, what will happen to you after you die?
The usual Buddhist picture is that we slide away into a dream-like whirlpool, driven forward by the "winds" of what is called "karma". You should understand that "karma" simply means action, and the idea is that everything that we have done, said and thought in our lives leaves powerful traces deep in our mind. These strong traces drive us almost inevitably to corresponding experiences. This is heightened in the after-death state. If, for instance, we have indulged a lot in anger, especially if we have expressed it in violence, we are likely to be magnetically drawn (whether we like it or not) to violent, unpleasant circumstances. Because we are confused in that state, we will tend to grasp at almost anything that seems stable, much like drowning person will clutch at anything that might look as if it floats. As a result we get sucked into a body of some sort as it begins to form, and eventually we are "reborn". It's not a very nice picture, but that is said to be the way it is.
I hope this helps a bit.