Casting physical fire from your hands in not going to happen. If it did you would be harmed in more ways than one. What you can do is learn to connect your energy to the fire element so that you can gather fire energy and redirect it via your body to help in your magical workings. This would be accomplished through meditation where you become aware of energy and the practice moving the energy around is an energy working.
Spend a lot of time as well observing different types of fire and learning to predict it's movements, color, and feelings. Fire is an element, spirit, living thing. It breaths , eats, and has waste.