Help with drivetrain

Hey everyone, sorry if this is a dumb/basic question, but my team is a first-year VEX V5 team and we’re still trying to figure out the basic part of things.

I’m a little confused about how wheels are usually connected to motors. How do the shafts, bearings, gears, and motors all fit together in a drivetrain? I’m especially confused about where the bearings go and what shaft/axle you’re supposed to use.

Thank you so much for the help!

A great tool to use for any questions about vex is YouTube. This is a good starter video! Good luck this year! https://m.youtube.com/watch?v=ajI2Czg_384&pp=0gcJCWQCo7VqN5tD&ra=m