first, you must parse the 3d data file and allocate the geometric informations into arrays(or struct, whatever suits your needs).
second, read data from the array and render it as usual.
actually, i see no problem here.
most likely, this is an assignment and you a just a beginning student. dont bother searching the net for loader, as this is custom made for your class. nobody even bother to make loader to this kind of data(ASCII, too many unnecessary words). there are other tips for optimization, but ill leave it for later, if you prove you can do the simple way.