Hello, 

I am looking to add a feature for the brides to be able to customize and preview their wedding invitations online. Is this designer suitable to do this. Are multiple font options allowed? Can it be configured to accept the customization of the several cards included in each suite, for example, main card, rsvp card and envelope? 

I do not have any programming knowledge so any help will be greatly appreciated

In general FPD should be suitable for this, yes. You can add a multitude of custom fonts either as .woff files or via google fonts. If all of these need to be customized then you can either put them in different views (I'd recommend that you check out the demo pages to get a general feel for the plugin: http://fancyproductdesigner.com/woocommerce/) or create one product for each item.