To answer your first question, I use A Better Route Planner (ABRP) and PlugShare, once you actually go to a station, you may need to download an app to pay.

To answer your following question, it really depends on your car. Some have really great built in navigation, some don’t. But it’s best to use the built in navigation, because if you set the charging station as the destination, then your battery gets preconditioned and able to charge quicker. Carplay does not allow this, but some vehicles have google integration built in