The everyday painkiller needing a prescription while stronger stuff sits on the shelf threw me too. My tip: bring a supply of your trusted basics from home for the first few weeks while you learn what's available here.
The everyday painkiller I've used my whole life needs a prescription here, while something I'd never buy without a doctor at home is just sitting on the shelf. The pharmacist has also been more helpful than any GP so far. What surprised you about pharmacies, and have you found them a good first stop for minor stuff?