Original
Maybe you can have a look over here:How to connect to wifi from command line ?How to connect to wifi from command line ?
It seems that NetworkManager is not necessary to configure wireless.
Maybe you want to install several Debian packages without internet connection to get things working. Please check over here for an explanation how to do that:How can I install software or packages without Internet (offline)?
Those two answers will hopefully get your wireless up and running. Please let us know if this works out, or where you get stuck exactly.
Edit
After you managed to install Debian by copying the full installation image to the laptop only the wifi problem is open.
A default driver for Debian for your wifi card is not supplied. However, a specific driver can be found here. You can check this video providing installation instructions for your specific laptop model, those are based on Ubuntu, but should be largely the same on Debian.