My contract for a rental property starts on June 1st.
The landlord asked if we can have the meeting where she hands me the keys on May 23rd as she is going on holiday. I said fine because I did not think about any financial implications.
Does this mean I am expected to pay rent from the 23rd? Or can I ask to pick up the keys later in that case, if I do not want to move in early?
I would be very surprised if you were expected to pay. If the contract says 1st of the month, and you got the key early because she was going on holiday that is not your problem, unless you agreed to something else.