A convention for direction
Scientists agree to use a convention which shows the direction of the electric charge flow (the current) in a circuit as being from the positive terminal of the battery towards the negative terminal. This is in the opposite direction to the actual flow of electrons – the most common moving charged particles in circuits.
How did this odd state of affairs come about?
The answer is that the convention was established before it was known that electrons move through the wires of a circuit.
However, the current direction convention is not important for understanding electric circuits and we'd suggest not making a big fuss about it in the models you develop.