Ledger Live is the official interface to view accounts, manage apps and approve transactions with your Ledger hardware wallet. This page explains how to "log in" securely — remember: Ledger Live does not request your recovery phrase.
ledger.com.You can set a local app password for Ledger Live, but the cryptographic signing of transactions always requires your Ledger device and PIN.
No — Ledger Live is an interface. Private keys stay on the hardware. However, malicious software or fake apps can try to trick you. Always verify sources.
Try a different cable/port, unlock the device, check firmware, or reinstall Ledger Live from the official site.
Yes — you can install Ledger Live on multiple devices. The Ledger hardware remains the single secure signer.