If your camera does not have a built-in intervalometer, don’t worry – you can get an external one very cheaply.
Basically attached to a camera it will take photos at whatever interval you set it to.
I have tried and used one of the cheaper cheaper ones. That’s a great way to get started. However, there is a company called Triggertrap that has a dongle that attaches to your smart phone and you can use a free app as an intervalometer. I really like using that.
In this video Nikon Ambassador Cory Rich goes over his camera settings and how he shoots a time lapse.