"read more" on excerpts on main page?

hello! i am trying to figure out how to add a “read more” or “keep reading” link at the end of excerpts on the main page. i’ve tried probably every plugin i can find and nothing works. the site is located at yamajnouna.com. could anyone guide me as to how to get a “keep reading” link to appear at the bottom of the excerpts on the main page? thank you for any and all help!