No map option on the left hand side to click?
No map at all?
Or just a patchy map?
In Chrome it works perfectly for me, but occasionally in Firefox i get a patchy map.
No map option at all - perhaps something is wrong with the HA install? The Map component is integrated, short of a reinstall of HA, I dont know how else to resolve that
As for the general functionality, take a look at this thread, and the links inside it
First thing Id do, is get your external DNS sorted, port forward in your home router, and then configure the owntracks app in your phone with the relevant details.
Once youve done that, the known_devices.yaml file should populate itself with your phones details providing youve got mqtt config right
If not, post any changes you made to any configs, any errors in your log, and the status of your owntracks app and we’ll see what we can do from there
Good luck 