Creating a Read More button within module

I am using the creativity template.
The site is http://www.makeupstarr.me

I wanted to add more testimonies so in the testimony section which can be found on the homepage if you scroll down, I added a read more button.

1. How do I center this button?
<p style="text-align: center;"><a class="bigbutton border" href="https://www.styleseat.com/makeupstarr">Read More</a></p>


2. The above url needs to be replaced to link to an article I have created in order to display more testimonies. In the past I have linked articles to menus which is easy, but I'm not sure how to link it here. I am not sure how to find the article url?

If there is a better way I should do this please let me know. If possible I would like the other testimonies to pop up in the same page.

Instead of using custom html module why don't you use news show pro.

Create a category such as testimonials in K2
Link module data source to this K2 category.

Create K2 items. Use Testimonial name ( persons name ) as K2 item title. Testimonial as content.

Use any one of the portal modes to display it how you want.
You might need to disable image and display text and title and read more button. Which will link to k2 item.

By the way very nice music in your website, very calming : )

See you around...