There are couple of issues which you can update and guide us to make it work.
- Your theme (Stuff Rentals) contains outdated copies of some WooCommerce template files. These files may need updating to ensure they are compatible with the current version of WooCommerce. You can see which files are affected from the system status page. If in doubt, check with the author of the theme.
- https://theemon.com/s/stuffrental/LivePreview/, The slider you have is flex-slider, which I dont have such in theme plugins.
I hope you will address this with urge.