WP backup question...

I am trying to help a friend of mine who has a Wordpress site. ( I am still learning WP ) It is just an informative site on a product that he sells...no shopping cart, just a custom theme WP with probably 14 pages if I had to guess off the main menus.

Long story short, I am first trying to help him backup the entire site since he does not have a backup, the people who created it for him are hosting it and he does not have the host ftp info. (It will take way too long to get it from those individuals...give you an idea he is an older person and they charged him $5k for the custom site...unbelievable) How would I go about easily backing up the entire site, including the custom theme and all info? When I click on "Backup" under tools on the left side menu in WP, it lists info under "These Core Wordpress tables will always be backed up" (see attached jpg) but it doesnt say if the theme will be saved?

I read when you go to the "current theme" section of the dashboard it is supposed to list where the theme file is saved and allow you to copy those files as well. However for some reason it does not show the file location of the theme.

Is there a easy way, or a plug in that I can install to be able to easily backup the entire site...custome theme, all media items, posts, pages etc?

I would be very grateful.
Thanks,
JP