The Replicate Layout plugin is designed specifically for this. It can make duplicates of the track layout, and place the footprints on it too.
If you want to do it the manual way…
This is not a problem. If you make a copy of some tracks, then they keep the old net name, for as long they are not connected to any pad of a footprint, As soon as you place a footprint on such a track, the net names will change to the new net, specified by the pads of that footprint.
I had not used the Replicate Layout in KiCad V8 yet, so I installed it via the Plugin and Content Manager and verified it still works.
I also agree with ML9104 here though. with such a simple setup, it is not such a big deal to do it manually and the benefit of the Replicate Layout plugin is not very significant.