You wont know if you have any thing anyone wants to hear until you have been embarassing yourself for awhile. Each time you do, notice the reactions, strive for the things that get you the smiles and nods, and note in the back of your mind those things that get the faces like when you scratch a blackboard with fingernails. I found that busking was a great way of developing as a musician, as the coins in your case were an emidiate way of guaging what works and what doesnt. But dont get discouraged by first attempts, like anything else, it takes work, and you will not be as good in public as at home for a while, and then, reacting to an audience, if you have tallent, you will be better for the interaction.
Good luck
Larry