There is no landing process, landing process is needed to complete PR process. For inland applicants, there is no such requirement. The letter is final step for PR application and that is it.
Letter is Valid for 1 year from the date of issue, after that you will need you PR card to prove your status and apply for benefits. (Remember not having PR card or having an expired one does not effect your status, you are still permanent resident).
Service Canada is no longer accepting SIN application in their service centers, you either have to apply online (of course preferred) or by mail.
for your health card you to visit the center. You can't apply online. You can use your COPR you got. Just print it out along with other document it should be no issue.