Hi, I didn’t see the answer if you only have your pc and no other big storage :
If you still have the installation usb or recreate one. Boot on it then you open gparted with that you remove the two partition off windows, the main with the system and the recovery one (if there is) but don’t touch the first or last partition esp if it exits. Then you can expand the partitions to get the free space. Extend to the right is fast but extend to the left can be really slow and prone to failures.
I case you Linux partition are all on the right you can also create new main partition, do the install of the linux on this one, then reboot on the USB, move the user and configuration files on the new system, delete old installation partitions, then extend the new install to take the full drive.
There is commands to remove the old esp entries I don’t remember yet.
This can take few hours so be patient.

The other option with a backup (dd) of the main partition is obviously safer but take nearly the same amount of time and need an external drive.

Most of the “software that runs only on Windows” runs perfectly on Linux with wine, including the installation software, and the integration into the app launcher on all of the Linux distribution that I know.

For a widow manager, I don’t use one, i have many virtual desktop and as it’s smoother than in Windows, I use only that (i don’t remember how virtual desktop works on ubuntu)

Première run really badly in VM, and run it with wine is highly messy, do to poorly designed Windows install soft and plenty of missing dependencies, there are linux alternatives that do nearly the same job : KDEnLive, Shotcut and Openshot.

That all I can tell for now, I hope it will help you a bit. Ps: try other linux distribution before doing an installation to find the desktop manager that you prefer.

*wake-on-LAN