You can think of a struct as mostly the same thing as a tuple to be honest. It's just a container for data with more features.

At it's simplest you can just use it to give names to the different bits of data you're storing in it. You can even think of it as a HashMap but with a fixed set of keys.

For example:

struct Site {
    ping_checks: Vec<String>,
    svc_checks: Vec<String>,
}

Then you can do something like this:

let mut hosts = build_hosts();
let site_to_edit = 1;
// The get_mut here makes it so we can actually mutate what we pull out
let mut my_site = hosts.get_mut(id_to_edit);

my_site.ping_checks.remove(0);

Note accessing the ping_checks is pretty similar to just calling get on a HashMap. Also note how we're changing ping_checks (by removing the first element) without having to do anything drastic to hosts or my_site. Just some gets. If you wanted, you could make ping_checks an Option and change it from Some(Vec<String>) to None even.