Upvote:1
We did essentially this same thing last spring. I used a passport holder that hung around my neck but under my clothes to hold my passport and any travel docs. other than exactly what I needed just then, also my emergency credit card. I never carried much cash at a time, preferring the international VISA debit card I got at my bank before going. The hostels I stayed at each had small lockers which my backpack fit into quite nicely, so I locked things up there during the day while I was out and about. I carried with me only a small messenger bag that held my tablet - left the larger laptop at home. Germany is a fairly safe country, that helps. Take good precautions and all should be well.