One thing I would recommend first is to familiarize yourself with the software by looking at the provided presets and understanding how they work. This may also inspire the artistic direction of your fire as well. Let me know if you have any questions about achieving that!
You can create a primitive shape like a cube and use it as an emitter, and then keyframe the scale of it to match the speed at which the fire grows. I would try that first and see how you like the results!