Customize border and button

Site URL: https://chateauboll-pamelahsiung.squarespace.com/

Hi! Can someone show me how I can increase the border for a button? Thank you!

website: https://chateauboll-pamelahsiung.squarespace.com/

password: brineintopedro 

This is what it should look like: 

Hi,

I think you need to recreate whole section with Code Block.

I see left has some text. They are fixed, or you will insert a link...in it? Just wanted to be sure, so that we can send the correct code for Code Block

The left will look like this. So far I just have text boxes so it looks like it. I won't be recreating the left side, only the "Book" button.