change slider

Is that part of your theme? IF so, I’d suggest asking the developer of your theme – as we have no way to help with commercial themes –

https://codex.www.ads-software.com/Forum_Welcome#Commercial_Products

I don’t think it’s a template. I believe it was custom done.
I had someone running my website and we have recently parted company, so trying to learn this and figure out what he did, but can’t find any kind of help for this particular issue

Unfortunately, can’t tell much from looking at the site or the code visible in a brower, so you might try asking on the theme’s support here:

https://themeforest.net/item/multipurpose-responsive-wordpress-theme/9219359

Or you’ll likely need to hire someone to look at the backend of the site and see how that’s coded. That’s outside the help available on these forums, but you could post a job listing here:

https://jobs.wordpress.net/