Q: Can anyone become a witch?
A: Most.
Q: Can anyone become truly powerful?
A: It's not a matter of whether most can. It's a matter of whether most people have the wherewithal to pursue their Art to that extent. If you have what it takes to become a regular user of magic (as a way of life) you likely have what it takes to achieve true power.
Q: Can someone here teach me to use spells and/or become a witch?
A: Some can, but be very careful in whom you choose to teach you. A good teacher will usually not ask for money, or expect you to immediately subscribe to a specific moral code.
Q: Do you guys believe in gods?
A: Occult philosophy ranges from devout religious practitioners to staunch atheists.
Q: Do you have to beleive in a certain set of gods to become a witch?
A: No.
Q: Is harming people with magic wrong?
A: Some say yes, some say no. Individual philosophies on harmful magic vary from tradition to tradition and even from individual to individual.
Q: What about the threefold law? Don't we get back what we put out times three?
A: Some say yes, and again some say no. My personal opinion on it can be found at this essay: Threefold Law?
Q: Will magic make me happy?
A: No. Magic will not make your life easier--it will actually create many problems for you if you do more than dabble. It will not make people like you--it will make those who know of your talents distrustful of you and even hate you. It will not solve your problems--what situations it rectifies on the mundane level are only amplified in more sublime ways.
In short, magic will not make the world a better place for you. What it WILL do for you is open you to a whole new realm where you have greater difficulties and a greater degree of control over your environment.
If you have *ANY* doubts about yourself, your willpower or your comfort level, do not practice.