I understand what an active and inactive object is, but I can't figure out how make an active object, inactive once it's on the timeline? Or, how to add a pause point to the object when it's on the timeline.
I did it once by accident but cannot replicate it.
You mean interactive and static objects (official terminology)?
You may ignore that interactive objects seem to have an Active and InActive part, separated by the Pausing point., which is not honored in HTML5 output. The inactive part of any type of button remains active, but the play head is released and will advance. If you want to make the button inactive in its 'inactive' part, but visible, you'll need an advanced action to be triggered by the button, where you add the command 'Disable' on top of the other needed commands.
To answer your quesstion: you need to use the Timing Properties panel to add a pausing point to an interactive object like a button if you deleted it by accident. You can time the pausing point in that panel, its default value will be at 1.5sec after the start of its timeline. You can move the pausing point also by dragging in the Timeline panel.
More about pausing points:
Not sure if this applies, but if your question is about how to disable an interactive object (e.g. a button) so that it does not respond to clicks then you need to use the Disable action.