Switzerland has a gatekeeping system: your GP (Hausarzt) is your first point of contact for non-emergencies. You don't need a referral for most specialists, but it's helpful to have a GP who knows your medical history.
Finding an English-speaking GP
Many doctors in Zurich and Geneva speak excellent English. Ask your health insurer for a list of in-network Hausärzte near you, or use your insurer's online search tool. Swiss90's directory lists verified English-speaking practices.
HMO vs. standard model
If you chose an HMO (telemedicine-first) model for your health insurance, you must call the telemedicine line first before seeing any doctor. Standard model insurance gives you freedom to choose any doctor directly.
Emergencies
Call 144 (ambulance) or 145 (Toxikologie), or go to the nearest hospital emergency department (Notaufnahme). Carry your health insurance card at all times.