Odom and CML_VEL not showing up in when I call 'rostopic list'

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The Navigation tutorials are rather extensive, including many tutorials for specific robots. A quick internet search will find many video Navigation tutorials, tutorials for publishing odometry, etc.

If you don't see a topic with rostopic list, that means no nodes are publishing or subscribed to it. For navigation, you'll need an odometry node to publish on /odom. Your robot will also need a controller node to subscribe to /cmd_vel, so it can follow commands. The controller node will be specific to the (type of) robot you have, but one common type is differential drive.

There is a steep learning curve when starting out, so I recommend following a well-established and self-contained tutorial (e.g., TurtleBot3) before trying to implement things on a custom robot. If you run into specific issues, feel free to ask more questions.