Your invitation for medical exam will include details and most likely clinic where you do it will provide information. But in general.
Bring prescription / medicines that you are taking.
Bring passport for identification.
They may take a picture.
If you use specs, bring them.
If you suspect yourself of being pregnant, do check that before coming. X-Rays can be avoided in such cases.
Invitation letter from IRCC having your uci.
I am not aware of vaccination status. Those are country dependent. I had to NOT present that in India. Will it be required in yourcase? I dont know.
It is unlikely vaccination status may be the reason for medical inadmissibility. If you have active/latent TB for instance, you will need to take anti TB treatment and under go a medical surveillance in canada.