If this is a fresh install of raspbian buster with desktop(GUI) by flashing the img directly to the SD card using etch or some other means then once the pi has rebooted the first time to expanded the image it should just automatically run the desktop no need to log in.
once you have used raspi-config to enable VNC and change your password , again following the reboot you should just be logged straight back in to the desktop.
there is no need to change any boot options regarding the desktop or logging in.
to log in via VNC you just enter the IP address of the pi in VNC viewer on your pc, then change the user to pi and then enter your password in the credentials window.
So if your pi is not doing this please explain what changes you have made to prevent this automatic login to the desktop, or access via VNC
if you have added another user then I don't know because I have not idea how you created the user or what access the user has.
I would suggest you start over flashing your SD card with a fresh copy of raspbian with desktop and try again, only this time only change your password and enable VNC don't change anything else.
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported