Does taproot change how private/public keys/addresses are generated, or just how the transactions are signed? Also, I'd appreciate if someone could recommend me where to look for official sources of documentation for transactions building, since I'm developing a wallet application.
No, Taproot does not change how private keys and their corresponding public keys are generated. The same secp256k1 curve is used, and public keys are still points on that curve. What Taproot changes is the signature algorithm used for Taproot outputs and a few other script things. You can read the full specification in BIPs 340, 341, and 342.