I just put it in my shop. I found it as a random event. Should I use it instead? What would happen?

You'll get a random amount of CSC for it. It can be 1. Selling would be a better choice, but that's my opinion.

i never got it

you either get csc (less than 25) or a random cash shop item costing less than 75 csc . You also get an achievement for using one :)

I'll do it :D