I'm pretty sure it can't be done with fullscreen - or I've never found a way, so would be happy to learn something new;-)
I've found fullscreen has a tendency to always add to the right of wherever you are. It also, even worse, then doesn't appear to register as a 'real' Space so you can't call it directly by Ctrl ⌃ number
My workaround has always been to use things maximised rather than fullscreen, then pin them to specific Spaces - Right click in the Dock > Options > Assign to…
That then regains my ability to instantly transition to that specific Space & always know which App/s belong there.