When you say "university staff", do you mean professors, or some other technical support staff?

If professors, then reaching out by email is probably a good way to start. They may get a lot of emails though, so your best chance to get a response might be timing the email right at the start of summer when they hopefully don't have any ongoing classes.

In terms of payment - most professors would happily talk about their areas of study with interested people for a short time (for free). If you needed a significant time investment from them though, then you might start having issues.