How to get gas on Aptos?

Excuse me, I'm new to the world of Aptos and I'm having a bit of trouble understanding how to get gas for transactions on the network. Could you please explain in simple terms what gas is on Aptos, and how exactly do I go about acquiring it to facilitate my transactions? Is there a specific process or platform I should use? I'd appreciate any guidance you can offer to help me navigate this process. Thank you in advance for your assistance.