You can do your backup quite easily. First you would need to know what your web site consist of and thus what should be backed up/restored. Usually sites are composed of files and databases. You must take care of them all if you want to have your site exactly the way it has been before.
In order to backup your files, please download all the files from your public_html folder to your computer by using your favorite FTP Client. After that you can easily upload back the files to your hosting account and your website will be restored.
Once having all the files on your computer, you should make a dump of your MySQL database.
You may also request an affordable backup creation of your whole account by contacting our technical department.