Customize & Home Page

Hello,
I am having trouble getting my customize to load in my roots theme. I have deactivated all the plug-ins and that did not change anything. I am new to wordpress so not sure what else to try.

Also, this website was designed by someone who is not longer at our church. I do not know how to find the text “Welcome to Cornerstone” that is on the homepage or the logo at the top..is that in the customize section that wont open because it is not on the edit homepage section?

And, lastly, on the homepage in the right side bar area is a white empty box. How do I delete that so that my text flows across the whole page?

I know there are a lot of question, I would appreciate any help!

https://www.cbcida.com/