I have seen few questions about mountaineering in Peru, but for those who look for mountain climbing in Peru, the best region is the Santa river Valley, usually known as "Huaylas alley" or Callejón de Huaylas. The Huascarán is the highest peak of Perú, and it's the landmark of the Huascarán National Park, where there are lot of beatiful lagoons so beyond climbing it's also a great place for hikers.

I found this article for beginners.
Five peaks in Peru's Cordillera Blanca for beginners