HI @Anonymous,
Correct - joints limit degrees of freedom based on geometric relationships. For instance - a rigid joint limits the two components (picture two plates even being joined on one face) in all 6 degrees of freedom, hence why it cannot move after (assuming one component is grounded).
And yes - I cannot stress enough about creating components from the get go if you plan on having a multiple component model. For instance, if it is just one component, a screw for instance, this would live under the top level component so there would be no need to create another one.
Regarding the timeline - It really depends on your workflow. If you come from a direct modeling background, then you may find that operations and modeling are easier for you if you disable the timeline. I find the timeline useful if I need to make parametric changes and have it update my entire model. For instance - lets picture a cube right. You'd start with a 3x3 square, then extrude it 3 inches. In DM - if you wanted to change the shape, you would either offset the faces, or cut away to change it to be 2x2x2. In parametric, I realistically would have created parameters for length, width, and height of the cube, and all I would have to do is go into the Parameter table from the Modify menu and then update the length, width, and height values and have the cube update automatically. In a more complex example, the parameters could save me from having to redo an entire model based on slight geometry changes.
You may want to even explore doing a hybrid blend of DM and parametric depending on your use case. For instance, we can temporarily turn the timeline off by using Base Features. If you go into the create menu you will see Create Base Feature. If you click this, the timeline will be turned off and you can DM until you hit Finish Base Feature. At which point your timeline will reappear and you will have only a single entity in the timeline for all the modeling you did in the base feature.
Thanks,
James Youmatz
Product Insights Specialist for Fusion 360, Simulation, Generative Design