It isn't scary, it's really like a bicycle that pedals itself. The power of a stock bike would be perfect if you are nervous. But of you get a good brand, you can always increase power. And you can tune that power for either more acceleration or top end or both!
They so not wheelie or have motorcycle power stock, basically you turn the throttle all the way from a stop and will slowly accelerate up to 30 or anywhere in-between. Every bike is different, but that's basically the deal.