It sounds like you've figured out the gimbal part of your question, so I'll focus on the second half: taking photos automatically for a timelapse.

Some cameras have a timelapse feature built-in, your camera may already have this capability.

If your camera doesn't have a built-in timelapse feature, then you'll want a tool called an intervalometer. An intervalometer is a small device with a cord which plugs into the remote shutter release port on your camera to trigger it to take photos. You configure the device with the parameters you want for your timelapse (such as "take a photo every 30 seconds until 500 photos are taken"), then press the Start button, and it will use the remote shutter release to take the photos automatically.

Intervalometers often have other features that may also be helpful, such as a self-timer (which can be used to delay the start of your timelapse, OR simply to give a longer delay than your camera's built-in self-timer) and a bulb timer (which will hold down the shutter for a bulb exposure for a specified duration). They also usually have a "dumb" shutter button that allows you to use it just like a regular remote shutter.