It depends on your abilities, knowledge(as Aimee said). and energy as a witch. If you're just starting, I'd reccommend doing some research on the Craft, my first year of interest in the craft that's all I did.
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Replying to:
Merry Meet Anonymous, and welcome to the wacky world of wicca!
Now in answer to your dear question, i inform you that it was in fact 3 years before i did my first spell, and it was only a sabbat ritual!
Now after reading that, know that for me it's different because i see myself as more of a studyer and seeker than a spellmaker and so with each step further into the craft i took, i kept deciding to wait out my time and not push myself as you too should feel able to do.
But, having said that, if you want to do a spell then i suggest you do it when you have confidence in your abilities and knowledge of the craft, and, abide by the witches law!