I'm a polish citizen currently residing in Australia.
i'm going to hold workshops and get paid while visiting the US.
What visa should i get ?
I'm also looking for a visa expert to help me with that.
That would be a temporary employment (H1) visa. You cannot work on a visitor or business (B1) visa, and what you are proposing to do is considered work.
There is no need for a visa expert to help you. The embassy will give you a list of the documents required, and the rest of the process is rather straightforward as long as all your documents are in order.