Is alternating current dangerous?
Yes, do not stick you finger in a light socket!
The normal electrical power in your home is alternating current. And it is dangerous. But it is dangerous because of its voltage, not because it's alternating. Alternating current of a low voltage, like 10 V, is not common but would not be dangerous if you ran into some.
The danger of electrical power is not significantly related to whether or not it is alternating. It is the magnitude of current that affects whether or not it is dangerous, and it takes voltage in excess of 12 V to cause a harmful current to flow through a person.
I hope this helps,