Travel vaccinations… what a drag. Unfortunately, you need to start thinking about vaccinations for Peru well before you travel, as some vaccines require multiple shots or need to be administered a certain amount of time in advance.
If you’re going to take a laptop to Peru, accept the fact that it could be damaged or stolen. If that would totally ruin your trip, sending you into uncontrollable floods of tears, you might want to consider leaving it at home.
Most backpackers will not have much contact with the police in Peru, apart from at border crossing points and checkpoints. Situations can arise, however, so you should know beforehand what Peruvian police are like.