There really is not much for you to do to maintain your PV system.
However, it would be a good routine to check the PV system production each month and compare to your utility statement.
You should also ensure that any breakers or switches are always in the “on” position. Please also make sure that any communication device and/or connection is on and/or properly connected. If the monitoring is connected to your router, it must stay connected. If you replace your router and it is being used to monitor the PV system, please check to ensure that the connection is reestablished.
If the modules are soiled, that could have an adverse effect on electricity production so you may want to clean them. If that is the case, please see below.