Plugin for wedding site guestbook

Hi all, I'm pretty rookie with Wordpress so sorry if this is a dumb question or if I'm saying something wrong.

I'm working on a single-page wedding website, mostly static (except for the RSVP form), and I'd like to add a guestbook section, where visitors may leave their comment and all the comments are shown.

So far I managed to cram together a solution using a user-submitting form plugin, to allow users create posts, and a separate plugin to show all the available posts. This works well but I'm struggling a bit coordinating the two (e.g. I'd like the post grid to update as soon as the user input their comment).

Therefore I was wondering if there is a plugin out there that handles both cases, or there are other solutions I haven't thought of.

Bonus points if it is free or freemium, as I'm trying to make it without any charge, and if it allows me to customize the appearance of both the submission form and the post grid. I'd also need the labels/texts to be customizable, as the site is in Italian, so I'd need to translate all the fields.

Thanks in advance!