Website Font

Hi!

The speed of my website is very slow, so tell me which is the lightest font. I saw on a website that there was an “Inter, Serif” font, so that website is very fast. I want to put “Inter, Serif” on my website but my website does not have the “Inter, Serif” font so please tell the code.

And also tell which is the lightest font.

The page I need help with: [log in to see the link]