No one is going to cast a spell for someone they dont know.
And if someone should offer, they usually ask for money, or something in return.
These are scammers, and should be avoided.
If you wish to learn how to cast, then you must start at the beginning.
Learn what Magick is, what it does and does not do, and The Basics.
This usually includes Meditation, Grounding, Centering, and Shielding.