I did the following steps:
-> Create/Restore wallet -> default_wallet -> Import Bitcoin Address or Private Key (scanned the QR code of the paper
wallet with an USB cam) -> Wallet -> Private Keys -> Sweep -> scanned the QR code with an USB cam
I think you're confusing Importing and sweeping. Importing a private key creates a wallet with your current private key and address, allowing you to interact with the funds. No transaction will be created when importing a private key.
Sweeping a private key will create a transaction, sending the funds from your old address to one of the addresses currently in the wallet. This is something you'll do if you did indeed create a HD wallet with a seed. Since you didn't create a "Standard wallet," I don't think that's what you intended to do.
But you already exposed the cold-storage private key to an online machine for nothing.
The OS is safe at least.
I'm not sure the OP did expose the key on an online machine. It appears he may have been successful in creating the Imported wallet, but then proceeded to attempt to sweep it afterwards. If he imported on an off-line machine he wouldn't see the funds, and maybe that's why he attempted to sweep it... Just a thought, I can't be certain without more information.
Sparrow also supports all 3 script types (+taproot) and offers a more user-friendly interface by presenting script options as selectable choices. However, you'll need to manually install Sparrow on Tails, whereas Electrum comes pre-installed.
Sparrow doesn't have provisions for importing an existing private key, it can only create HD (seed phrase) wallets. Once that's done, however it will sweep it an existing private key.