sorry I was in bad mood yesterday, and was a little direct.
Glad it worked and you found it easy because it is, and people should all do that instead of trying neek on random guide on internet. which guide did you try to follow? apparently it's a bad one, and It could be useful to know which one you used so we can contact the author and make it delete it or update it.
USBLoaderGX is a game launcher, and can launch directly Wii, channels on NAND, channels on emuNAND, gamecube (yes it can!) or homebrew.
If you want to play gamecube game using Nintendont instead of normal gamecube mode of the console, then you use the "homebrew" launcher method of USBLoaderGX. it launches nintendont and tells it which game to boot.
there are two other gamecube mode you can use :
- Devolution (another homebrew, working the same way than Nintendont),
or
- MIOS (internal, official console's gamecube mode, without using another homebrew), which itself has been patched and few different developers made different compatibility :
-- MIOS : normal gamecube mode of the console, launch retail gamecube disc, or burned gamecube disc if you have a modchip
-- cMIOS : launch retail and burned gamecube disc, even without modchip, only on old console compatible with DVD-R
-- DIOS MIOS Lite : launch retail disc and ISO from SD
-- DIOS MIOS : launch retail disc and ISO from USB
-- QUAD FORCE : launch Triforce arcade games ISO from SD/USB
By default, the loader used MIOS mode, but now everybody want to use Nintendont so I changed the default mode to nintendont. users don't even remember the Wii could play Gamecube natively, but the option is still there.
Now for your question:
if you choose "real NAND" you can't delete channels, it's the channels located on your Real Wii !
if you choose "emuNAND" then you can delete channels from it, it's just a copy of your console and there's no risk to delete content from it.
Two choices :
Choice1: delete channel on emuNAND only
top menu 4th icon > DISABLE "channel on NAND" and enable "channels on EmuNAND" to show only emuNAND content.
select the channel you want to delete, but don't start it, just press A once to have the animated banner with the two option at the bottom "option or start"
go to option
select "delete"
Choice 2 : hide channels on BOTH emuNAND and real NAND, but not delete the channel
follwo the guide at bottom on this post
https://gbatemp.net/posts/4251265
Remember that this "easy mode" which I call the cIOS emuNAND mode, is not 100% compatible with all games.
Castlevania is not working for example. that's one of the most wanted game, so you'll see it's not working soon.
There are other games, but less known, like bonzai barber.
these non working game will require the "neek emuNAND mode", which is 98% compatible (I guess).
but you noticed, neek is not easy to setup if you follow random guide. but it's as easy as what you did above if you follow a good one. it's only "generate files. Copy files on SD or USB. done !" but all guides from other people make that so over complicated that nobody manage to make it work.