Unsupported themes – what's the worst that can happen?

I’m a complete newcomer to Woocommerce though I have a rudimentary understanding of putting shopping carts together.

I have an established WordPress site with a theme that I really don’t want to change – but it is not Woocommerce-ready. I would like to add a commerce facility to it, however. What sort of problems am I looking at in unsupported themes and is it advisable just to install Woocommerce anyway and see how I go?

Thanks!

https://www.ads-software.com/plugins/woocommerce/