Hi ali9i,
1) For the upfront medicals, you have to go to an authorized medical center and request upfront medical exams, then they will create for you an IME# and after all the test are done the clinic will submit the medical test report to IRCC directly. They will also give you an information sheet, I scanned and submitted the information sheet to IRCC by Case Specific Enquiry online. In the CSE, I told them that I would like to attach the medical results to my PR application. After around 2 weeks I saw in my GCkey account and ECAS that shows "You passed the medical exam".
2) About the Pre-arrival Services notification, I am not really sure, I haven't heard of this before either. Just today I received a message in my GCkey, and the message is a letter named "Invitation to Pre-arrival services" and it basically says that "you and your dependants can now receive pre-arrival services offered by Canada". I've seen other people in this forum that have received this letter.
Hope it helps,
Regards,
We are in similar timeline and I got the pre-arrival services letter a week ago as well. Let stay in touch.. I heard that this is sign of PPR soon?