Happy to help @pollowach.
You can display the opportunities by adding the Volunteer Opportunities block to your page content. Once added, you can use the block’s toolbar to show one-time or flexible opportunities.
There aren’t currently any filters for the block, but the volunteer opportunities can be ordered. One-time opportunities are shown in chronological order with the soonest opportunities showing first. Flexible opportunities are shown based on their publish date. To change the order of those opportunities, you can modify the publish date.
The featured images aren’t shown by default when using the Volunteer Opportunities block, but there is a templating system built in to allow you to show them. If you’re comfortable with code let me know and I can send along the steps. The featured image will likely show when viewing a single volunteer opportunity, though that depends on how your theme is configured.
The volunteer signup form can be modified in a few different ways. Check out this question in the FAQs for details.
I hope that’s helpful. Let us know if you have any other questions!