LUKS, and removing unwanted volumes/containers

hey, query about LUKS and encrypted containers
i installed luckyLUKS GUI app on my linux, as wanted to test it out for encrypting a usb drive i have.. i may use for other things (as veracrypt doesn't seem to work for a few use cases (mostly external drives i've tried)). 
i'm not super techy, so appreciate the ease that luckyLUKS offers (assume most in here are far from needing such an app)... but not dived into LUKS cli usage yet, which is likely reason i have this issue!

i've spent quite some hrs trying to figure the app and it's functions out, but i'm obviously missing some fundamental understanding on how LUKS works on the backend.

for now, i've been able to encrypt a file, which i 'had to' create on my desktop (wasn't an option to create the encrypted file on my usb drive).... but not a big deal. i just copied it over when it was created.  (1st attachment)

so, i now have this encrypted file in my usb drive, which when i click to open > i can do, if i enter password... all great. and working well.

but, i seem to have created another replica/similar encrypted folder, which remains on my computer, when i eject my usb drive... i would love to be able to delete/remove this file.

(2nd attachment)

the other thing is, when i initially tried to create a file, a few days ago, i did so (well attempted to), and created a link for that file, which shows now in my start menu, as unlock vault (vault was the name i gave it)

(3rd attachment)

if this container does exist, it has nothing in it, so again i'd love to remove/delete... but i can't find it anywhere amongst the maze of linux folders!
i have the option to uninstall when right click the icon. but i think that will uninstall the function of creating shortcuts via luckyLUKS.

as you can see, im a tad confused.
if anyone knows a good basic, step by step tutorial, intro to LUKS, i'd likely benefit.. what i found on utube didn't help so much, as well as the sites i found.
but also not needing/wanting to be a master of LUKS CLI, but if i could safely remove these few pieces, i'd be satisfied (and of course, know the process, their location etc, so doesn't happen again).

thanks so much. sorry msg is so long. just felt helpful to share the various parts. 
regards
phil

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