Most of you will fly to Naples; we suggest early booking, as it is a holiday weekend in Germany and prices go up sharply.
There is also a night train run by the Austrian railway company that connects Munich and Rome. From Rome, fast trains to Naples take around an hour and a quarter.
From Naples Central Station to Sapri: From the Central Sation there are very frequent connections, either directly or with a change in Salerno (type: Napoli Centrale – Sapri). From our experience, the cheapest option is to book directly via the Trenitalia Website, which offers multilingual versions. You can also check the private train company Italo.
From Naples Airport to Sapri by car: Google Maps will suggest a route via the exit “Lagonegro Nord” from the E45. After that, it leads you through a curvy mountain road – not bad in terms of the landscape, but not the easiest trip for those who tend to get travel sick. Personally, we find the route via Policastro easier as it leads through a better maintained, less curvy superstrada for most part and then a bit along the sea. Here is the link to that route.