This is a tiny bit complicated. Energy is all around you (in the air, earth, plants, animals, water, etc...). You need to learn the basics which are meditation, grounding, centering, open your chakras, etc... to learn how to harness the natural energies around you. Of course in my mind people also have energy within them they can use, but stronger spells would require harnessing more power.
A secret place isn't needed, but a place that is quiet would be best.
I don't believe knowing your element is necessary, but you are normally harnessing energy from the elements so knowing it couldn't hurt.
energy is everywhere.....literally everywhere. theres enrgy in you right now! no you dont go to a special place...you dont need a element but some spells might require one. PM me if you want more info..
A lot of people tend to meditate first before casting a spell or perform a ritual, as too it helps them concentrate and focus on what they are doing. You have a lot of energy inside you already that you can use. You just really need to learn to meditate for about 20 to 30 minutes a day to help relax your body and clear your mind. You should practice with visualization and grouding and centering your energy. So that way no negatie energy comes into the spell or ritual you are performing/casting.
But remember you really should study your basics first.