I think I was born a witch, but took a few years to figure that out
Firstly - Wicca is a specific sect of witchcraft. Being a Wiccan makes you a witch, being a witch does not make you a Wiccan.
I have a family history of spiritualism and witchcraft, but one I only completely discovered when I researched my family history. I found that there were pagan believers going back many generations and verbal family history told me about the 'wise women' in my past.
I was raised to be aware of many religions, and investigated many for myself as I grew older. My main influence though was my mum who is a spiritualist so I did explore aspects of that more. I eventually discovered paganism and finally felt 'at home' with it and, as an extension of that, witchcraft.
Witchcraft is a belief in the natural energies of nature and ourselves. Witches use that energy to influence things, in the same way that Christians for example use the power of prayer.
The exact nature of the beliefs can vary - think of it in the same way as there are many versions of Christianity. The basic premise is the same, the fine points vary
Becoming a witch is a case of exploring your feelings, discovering the wonder and power of the natural world and translating that into a way of life.
Right, I have waffled without previewing. If any of that makes the vaguest bit of sense I will be pleasantly surprised
Feel free to fire questions.