Awesome date night opportunity!
We came because we wanted to try something different on a Friday night and neither of us are even remotely artistic.
They provide the canvas, the paints and the brushes. The instructor guides you through creating the painting that is the topic for the night. You can check on their website to see what is the painting of the night. However, you are also allowed to do your own thing or not follow the instructor on your whim.
Regarding alcohol, they do not provide any - that is why it is BYOB. They do provide plastic cups.
Our instructor was a lot of fun and had really good suggestions as we were painting.