Congrats on getting your L5!
Re WiFi, you might check your router transmission settings (band, radius, etc.) Maybe one setting will work better than others. And 2.4 GHz generally penetrates walls better, I think I’ve read somewhere.
Re GPS, it’s recommended to take it outside under a clear sky for a while. BTW, Pure Maps (flatpak) is generally more usable than GNOME Maps.
I’m not using my L5 as my main phone, so it mostly sits indoors, next to my laptop at home, and shows my position off by about 35 meters at the moment. (I haven’t tried leaving it outside in one place for a while.)