change font in menu area of Delicacy theme

Use CSS font weight
https://www.w3schools.com/cssref/pr_font_weight.asp

Thanks Andrew I got the code with your link, it is:
{
font-weight:bold;
}
But I am not sure where I put it in the css style sheet. I want the headings in the main area to be bold. Can you help.
Cheers
Sheena

Do you have a section of the dashboard named, “Custom CSS”, “Custom Styles” or “Jetpack”?