The car manages that automatically. By default, the car is set to not charge past 80% (what Tesla calls the "daily capacity"). You can go into the battery set

The car manages that automatically. By default, the car is set to not charge past 80% (what Tesla calls the "daily capacity"). You can go into the battery settings and set it to 100% ("trip capacity") which gives you extended range but takes longer to charge (both at home and at Superchargers). The Tesla manual specifically says to leave the car plugged in any time you're not using it and let the on-board energy systems figure out when it should be charging and when it shouldn't be. Every Tesla has a bypass where it will use the energy from the charger to power the systems in the vehicle without needing to charge it. Some other EV's charge the battery and then run the systems off the battery which results in a continual power draw/charge cycle which can shorten the battery life. You don't need to worry about that in a Tesla.