To change the font family of the file names, please try to use this code:
.eapp-file-embed-item-name {
font-family: "Archivo", sans-serif;
}
Just in case you’d like to add the title and change its font, here is the solution - Change font and size of the title.
As for the font size and weight, you can easily change it on the Appearance tab:
Check it out and let me know if it helped 