Hi and welcome!
A lot of the sounds are actually quite similar to the untrained ear and can only be interpreted by taking body language and situational context into account. That is the reason why you struggle to find more information. Piggies are generally good communicators, so they teach you fairly quickly what they like and dislike.
This is the best audio bites website with correct information:
http://www.jackiesguineapiggies.com/guineapigsounds.html
Guinea pigs are group animals and not really wired to live alone. Please consider getting your little boy a friend, ideally from one of our recommended piggy savvy rescues which we can guarantee for experience and good practice. The key to a stable boar bond is mutual liking and character compatibility; an age difference can also help with stabilising the bond while your little boy is going through his teenage hormones. You will have the added benefit of enjoying the antics and the lively interaction that makes guinea pigs so unique.
https://www.theguineapigforum.co.uk/threads/companionship.37654/
https://www.theguineapigforum.co.uk/threads/boars-a-guide-to-successful-companionship.76162/
Your closest rescues where you will be in safe hands are North West Guinea Pig Rescue and Rosie and Brambles Sanctuary.
https://www.theguineapigforum.co.uk/pages/guinea-pig-rescue-locator/
https://www.facebook.com/pages/Rosie-Brambles-guinea-pig-sanctuary/288075508063692
https://www.facebook.com/NegprNorthEastGuineaPigRescueAdoptionPage
As a piggy newbie, you will also find these threads here helpful:
https://www.theguineapigforum.co.uk...or-a-balanced-general-guinea-pig-diet.116460/
https://www.theguineapigforum.co.uk/threads/guinea-pig-body-quirks.58854/
