Switch to parallax scrolling on my established site

Site URL: https://www.christcathedral.org/

My site was built with some custom features in the header on each page (by a hired coder), I would like to switch to parallax scrolling but I am afraid of what it might do to those features (I am not a coder). Can someone look at my site and give me some advice? Thanks in advance!

It your site is a 7.1 site you will need quite a bit of code to make parallax scrolling function, and i don't know how it will work with the code already in the site. If it should cause a problem just remove it, simple as that. 

You site moves almost like parallax is there, just not as pronounced. 

https://www.will-myers.com/articles/parallax-in-squarespace-71