font 7.1 Custom Font for Button & Paragraph Styles Not Changing

I have just started working on a new clients site, and it looks like things have changed since I last created a website with Squarespace. I am using 7.1 with Fluid Engine.

Here's my issues so far:

• I am having trouble changing the font for the SITE TITLE BUTTON,
• all PARAGRAPH types,
• and removing the NAV from the NAVIGATION bar.

I added Custom Fonts in the Custom CSS area.
Then, selected those fonts in the Site Design area. 
The custom fonts have worked with the Heading styles, and the Site Title. For some reason, I haven't been able to get the Paragraph Styles and Button Styles to switch even though I have chosen those custom fonts in the Site Design area.

https://tucker-tradpole.squarespace.com/
To access, the password is tuckerusa. 

Any help is extremely appreciated. 

Thank you @tuanphan! Exactly what I needed.