Reddit mentions of The Travels of Mendes Pinto

One of the most amazing life stories I definitely recommend looking up is Fernão Mendes Pinto and his work "Peregrinação" (Pilgrimage). He as a common man spent 20 years roaming the Orient in the 16th century fulfilling roles from sailor to soldier to monk, ambassator, merchant, pirate and slave, and according to his account was one of the first europeans to reach Japan, as well as inland China.

There was an english version made by a man named Maurice Collis that I read, but it was an early 20th century book and I felt it was sort of old fashioned. Here is one in Amazon, though eh, it's kind of pricey.

Another which I recommend looking up (And which has an actual english translation for once) is Miguel de Castanhoso's first hand account of the 400 men expedition of Cristóvão da Gama, one of Vasco da Gama's sons, to aid the kingdom of Ethiopia from collapsing against the neighboring Sultanate of Adal who had the aid of Ottoman Janissaries. The Emperor of Ethiopia, as we know, was the mythical Prester John of Indies.

Here's a scan of a translation of his work, and here is a place with updated reprints.

As for the explorers it's technically only considered an "explorer" someone who's the first to reach a place previously unknown either by humans completely or at least the people in the homeland. So yeah, Vasco da Gama discovered the sea route to India, Pêro da Covilhã walked his way to Ethiopia in the 15th century, and António de Andrade is considered the first european to reach Tibet, to name a few.

Cabral is considered to have discovered Brazil in 1500 "oficially", for we suspect it was already known to the portuguese before that.