Good news, I figured out how to fix my double menu bar! What it was, was just a dock on the left and an Activities bar up top, which is I believe the normal setting actually, just I'd forgotten about it after having installed Dash to Panel. This is kind of how it looked (taken from here

I fixed this by uninstalling and then reinstalling Dash to Panel, and restarting my computer a few times in between. I was also sure to download its settings (via last tab in its settings) so I could reupload them. This is what they were:

[/]
show-apps-icon-file=''
group-apps=true
show-running-apps=true
show-tooltip=false
show-window-previews=true
trans-use-custom-opacity=false
dot-position='BOTTOM'
panel-position='TOP'
intellihide=false
panel-size=25
multi-monitors=true
dot-style-focused='METRO'
location-clock='STATUSRIGHT'
show-showdesktop-button=true
hotkeys-overlay-combo='TEMPORARILY'
show-activities-button=false
dot-style-unfocused='SQUARES'
show-show-apps-button=false
show-favorites=false
taskbar-position='CENTEREDMONITOR'
trans-use-custom-bg=false
window-preview-title-font-color='#dddddd'
appicon-margin=4
tray-size=0
show-appmenu=false
appicon-padding=4
isolate-workspaces=false

This is how my desktop looks now, with great joy borrowing Bing's wallpapers unofficially via National Geographic Wallpaper app:

You can see the problems I'm having with the system manager, Conky Manager, rendering stats all tiny on the right. This is one other thing I'm actively working on fixing. On top of this, we have:

• setting up snappy corners so I can have a quadrant of windows open at once
• hiding the annoying GRUB menu on boot
• re-enabling secure mode (and full disk encryption? I think that's gone too). I feel these are two vestiges of having installed the WiFi driver on my own
• figuring out (and resolving) what's causing the super annoying "System Problem Detected" message box that always appears a few minutes after boot:

I will detail my exploits here as they happen. In listening to Linux4Everyone I've realized that this XPS experience is going to be one big hackathon for me; that it's probably just the first in a long line of Linux experiences I'll be having over the years, and not to worry about perfection but rather just dive right into it and keep hacking at things until they work (eg: not seeking that fresh "American" install I mentioned before, if it even exists).

Bonus: I discovered how to about:config my way out of the annoying Firefox address bar spam ("Search With "; "Visit Website" options). And I discovered why the heck this is suddenly a 7000 series XPS when it's following the predecessors in the 9000 line: simple rebranding.

Dell only allows access to an image if you purchased FROM DELL with Linux.

https://linux.dell.com/

Support is available but it is not free.

Dell does not support buying windows and installing OEM Ubuntu afterwards.

https://www.dell.com/en-us/work/shop/overview/cp/linuxsystems

This is why if you buy a dell with windows you should do linux ALONGSIDE windows.

The 7390 does work with 18.04

Standard images of Ubuntu may not work at all on the system or may not work for all hardware.

This system was tested with 18.04 LTS, running the 4.15.0-1042-oem kernel.

https://certification.ubuntu.com/hardware/201906-27119

This system was tested with these key components:

Hardware details