First congrats on getting your test invitation. It is a multiple choice exam you will want to read the Discovery Canada book thoroughly a few times along with some online practice tests. You will need 16 correct out of 20 and you need to take all the original documents so your passport copy you submitted with the application for the relevant 4 year period if you have an older expired passport you would want to take that as well, your PR card, COPR letter. Ideally take all the original documents for which you submitted copies with the original application.