On the left here we have how the Testimonials could appear on your site. At the top there's a simple text box to fill in by your customer and optionally they can enter their name. In practice I would advise using an anti-robot protection system here, probably the free Google offering.

On the right is your Admin system to control what appears on your site. Once a testimonial has been entered, you will receive an email to warn you to come here and check what was written about you. You can edit the comment, delete it - or add a comment of your own, maybe a 'thank you'.

Appearing on your website:

We really wanted to let you know what a wonderful holiday we had with you! The cottage was a home from home and so peaceful, we really miss waking up and looking out on the animals and the mountains, it was so beautiful. Charlotte fell in love with Bandit and the goats and was very sad to leave. Thank you again, you have a truly lovely place to stay we could not have asked for better
Jane Doe 16/09/2019
I'd just like to say how absolutely fantastic everything was during our holiday, the accommodation was fantastic and the views were amazing. We will be back!
Joe Bloggs 25/05/2019
Glad you enjoyed your stay, please come again
Paul

In you Admin section:

10
Checked?
No
Live?
No
Date
16/09/2019
Text
This message is a new one, it has not been moderated, so it only appears in the Admin, not on the website. You would have received an email to draw your attention to this.
By
Anon
  Reply
  Reply by
9
Checked?
Yes
Live?
Yes
Date
16/09/2019
Text
We really wanted to let you know what a wonderful holiday we had with you! The cottage was a home from home and so peaceful, we really miss waking up and looking out on the animals and the mountains, it was so beautiful. Charlotte fell in love with Bandit and the goats and was very sad to leave. Thank you again, you have a truly lovely place to stay we could not have asked for better
By
Jane Doe
  Reply
  Reply by
8
Checked?
Yes
Live?
Yes
Date
25/05/2019
Text
I'd just like to say how absolutely fantastic everything was during our holiday, the accommodation was fantastic and the views were amazing. We will be back!
By
Joe Bloggs
  Reply
Glad you enjoyed your stay, please come again
  Reply by
Paul