The above is right and there's another term for an offline wallet which is called cold storage.
I recommend Electrum wallet if you are going to follow the suggestion above.

You can follow the complete guide on how to make Electrum cold storage you can find it from the link below.
- https://electrum.readthedocs.io/en/latest/coldstorage.html?highlight=usb

Then you can use https://coinb.in/#newSegWit to make a raw transaction and save it to notepad and save it to USB flash drive to transfer the copy of the raw transaction to your offline Electrum wallet to make a signed transaction.