after you enrolled. They will teach you step by step how to apply. You will also need signature from your uni HEP (hal ehwal pelajar) for your document to be certified. There will be few batches for the PTPTN crews to come collect your documents. So don't worry. You won't miss it.
from what I heard, past few year ago passport are needed to travel to east malaysia. During my year(last year) are not needed anymore.