A workshop would typically imply you will be expected to perform some tasks, otherwise it would be a "seminar", "lecture", or "presentation"
If there are required materials they should be listed among the information about the workshop.
From there, it's all guesswork. Some workshops will have everything you need provided. Whether that's merely a pencil and paper or a computer station greatly depends upon the company presenting the workshop and the topics to be covered. If everything is theory and principles, it may mean all you'll be doing is some wire framing on paper with pen, you may not need anything more than that. Certainly no one here would know.
What I would bring:
- A Laptop with appropriate software loaded (but really expect it to not be needed)
- A notebook and writing instruments (to take notes)
- A voice recorder (or app on the phone and charge the phone)
If you know the person facilitating the workshop, you can do a bit of research to see if they've written anything you may be able to read. Although probably not imperative, it may give you a bit of a head start.
Most of the sub-category (as in area within a profession) workshops I've attended in the past expect you to have general knowledge of the field - as in, jargon, terminology, basic software awareness, that sort of thing. The facilitator will often speak in technical terms/jargon which is common for the industry, and failing to understand that can cause you to struggle more than you should (or continually ask for clarification). Same goes for overall software knowledge. You should have some idea of the general software used in the industry by professionals and have a working knowledge of it, not necessarily at an "expert" level, but at least be familiar with it.
As for what you will be doing.... any guess here is as good as yours. In fact, we have even less information than you do.