Is anyone here really adept with VMs, the VirtualBox type in particular ?

I’ve been striking out right and left with this so far. The manual is quite lengthy and possibly too complex for me. Maybe not here at VH, but where is a good place to ask questions on this and get some guidance ?

The shorter, simplified guides that I’ve tried have gotten me nowhere. For example, Win 10 Pro is supposed to be able to directly mount a VHDX file, but when I tried to do that it said I’d first have to format the storage HDD on which the file resided. But that storage was already formatted NTFS, and if I’d said ‘Yes’ it would have trashed everything that was stored on that drive.

I installed VirtualBox 7, laboriously converted the VHDX image to VDI (the VBox supported Guest OS image type), only to find that the VDI file could not even be seen by VirtualBox. So, at this point I’m clearly out of my depth with this.