Doing first cross country flight plan with several stops along the way. What is the general rule of thumb for calculating time, fuel, etc. for a mid trip landing? I've done conceptual flight plans with checkpoints etc, but not actual stops.

In other words, I can calculate fuel burn, ground speed, course etc. for a point to point flight. Just not sure what to calculate in by adding a full stop in the middle of that same flight.

While studying for the FAA knowledge exam it sometimes said calculate 3 minutes for take off and departure but curious if there is a generally accepted set of numbers.