If you plan to have a wired Ethernet connection to manage the Powerwalls and Solar inverter, then you should have that setup and ready for them to pull through conduit. Remember that electrical code requires shielded Ethernet, at least the stuff that the installers pull throughout conduit and panels.
If you plan to use WiFi, make sure the installation area has a good signal.
If you have not yet considered networking, then uh oh!
By default, installers will do the minimum work, which is leave it to built-in cellular Internet. But you will get slower reporting on your equipment because Tesla and the solar are paying the cellular bill and will throttle traffic to save money.