Imagine that for some insane reason, you set up a pipe underwater. On one end of the pipe you put a pump that pushes water into the pipe. At the other end of the pipe, you put a vacuum that sucks water out. In the middle of it, you put a turbine that powers a lightbulb. When you turn it on, energy flows from the pump to the turbine because the pump pushes the water. Energy also flows from the vacuum to the turbine because it sucks water out.
Batteries work like that, but with electrons as the medium. Negatively charged particles repel electrons, and positively charged ones attract it. So when you make a circuit, the negative terminal pushes electrons away from it and the positive terminal pulls them, resulting in both sides giving energy to the load.
> Is this how you could explain alternating current for transportation of energy?
This part I don't grasp super well, but I'll take a stab. It's a higher level thing. Resistive losses are relative to the current squared. So you want low current. But you need to deliver a lot of power, so you have to raise the voltage. Normal people's homes can't handle 200,000V power, so you have to convert it back to a lower voltage before you put it in people's homes. The cheapest/easiest way to do that is with a transformer, which requires a varying current (i.e. no DC).