I would like to do a health check. where do i go to get blood tests done in cape town / northern suburbs? secondary objective is to donate blood)

Try looking online: Years ago, listings used to be available only in printed form. By the turn of the century, lists had become available online everywhere. Now, some lists are only online, and no longer printed. County medical societies (or other local medical societies), hospitals, or insurance companies usually list doctors by name, specialty, and location. Look for Primary Care, such as Family Medicine, doctors.