Several Problems after installing a wrong Debian 11 iso

I made a mistake during the installation of Debian 11. My plan was to run Debian next to Win10 by using Grub2 but installed Debian high secure LVM which overwrote my notebook’s complete Harddisk. I am completely new to Linux so as you can imagine I struggle hard because I only have a “DOS-style-Terminal”. The Debian 11 .iso ist only 3xx mb large and I wonder if i am able to install Gnome from the given Terminal. Some sources mentioned Gnome could be part of the .iso .Is it true? Do I have a chance to process? If not I concidered to add a folder on the bootable USB stick, add something like “gnome.deb” and try to progress this way. I dont have internet in my Asus Vivobook model M712D because of missing”RTW88……” which makes my situation even worse but can access the internet by my Smartphone. I want to Download Gnome by my mobile, save the .tar.xz file on an mmc card and install it. But how to unzip the xz-utils.tar.gc file with this minimal debian version i mistakenly downloaded to the point my windows was running? Mounting a mass device works, but i cant perform something like apt-update… Do i have a realistical chance to progress by mobile+mmc to make my notebook ready again?