Can someone explain how i can use this to find the position for x and y on the 2d plane that is 600 * 600 pixels.
Assuming that you want to compute the position that an arbitrary 3D vertex (x,y,z,1) has on the view plane after the projection: You can use the given parameters to compute a projection matrix:
f = cotangent(fovy * 0.5)
This is also the matrix that will be set by a call to gluPerspective. Then, you can multiply this matrix with your vertex to obtain the projected vertex position.
Generally, you have to use a bunch of matrices. With the traditional OpenGL pipeline, you'd have to mutiply these matrices:
finalMatrix = modelMatrix * viewMatrix * projectionMatrix * viewport.windowMatrix;
To find the position of the vertex on your viewport, just multiply the vertex by the matrix:
onViewportVertex = in3dVertex * finalMatrix;
Of course, this implies that no shader modifies the vertex or the pixel.