The purpose of the 7805 is to produce 5V from a higher voltage. If you use a 5V wall charger, you don't need to do that.
There are lots of other tutorials. Look at a few and study how they wired everything.
Note that most of them suggest using the 5V output from the Arduino to power the motor. That will work for one very small motor, and perhaps for one 28BYJ-48 motor, but it is a bad idea in the long run.
In general you need a separate power supply for motors and servos, and to connect the grounds.