Gears - can someone give me a configuration, or else ELI5?

Hi all, First of all I'm sorry if this is tagged wrong, maybe it should have been differential / gearbox help instead? But honestly I just don't know what that means so I thought question seemed safer, but I apologize for my ignorance on this matter. To the point of the post: I have tried reading up on this matter but I am unfortunateltly dealing with mental burnout right now, so all info about torque and ratios and stuff sadly just gets me very overwhelmed and confused. I am hoping that a...