Help with CSS code for font usage?

Site URL: https://www.tinythai.biz/

Hi All, having some trouble using a custom font and it not showing up universally on many pages, which is frustrating. Are there any CSS pros would could give me some pointers?

On this page:
https://www.tinythai.biz/blog
The header and date entry are not my preselected fonts

On this page:
https://www.tinythai.biz/pop-up-events
The meta data (date, time location) and large date are not my preselected fonts

 And finally on an events page like this:
https://www.tinythai.biz/pop-up-events/hot-take-wing-pop-up

The "back to all events", meta data (date, time location) and next event info at the bottom right are not my preselected fonts

I know it's probably a matter of just dumping some code in the CSS box, but after scouring these forums, I don't have a clue! 

Any help is SO APPRECIATED!!

TY!!

Hi. Custom font or Squarespace font?

@tuanphan it's a custom font not included in Squarespace. Any magic tips would be SO APPRECIATED!!

Hi. Have you solved it yet?

@tuanphan indeed - ty!