When you are looking at items in the online store, there is a link to the Lodestone database record for each item under the "purchase includes" heading.

So for example, this is the page for the coat:

https://eu.finalfantasyxiv.com/lodes...em/80ab02e9793

You can see that it is listed for "all classes" and "Lv.13", so that tells you that you can use it as a glamour (or directly as equipment) for any class, but if you're applying it as a glamour, the gear you're applying it to also needs to be level 13 or higher.