Backup help

Hi Guys,

A bit of simply advise would be appreciated. I need to back up my site before I update to wordpress 4.0. I have never backed up a site before and despite running the risk of ridicule I wondered if one of you could tell me the best way to do it.

Do I simply log in to my ftp (which is godaddy for my sins) and save the main files to my harddrive. Or do I use something like ‘UpdraftPlus Backup and Restoration for WordPress’ which gets 5 stars on feedback?

I want to back up the theme and files and all of the listings as well. The longest part of building my site was configuring all of the custom taxonomies so I don’t want to lose them.

Once saved, can I simply use these file and add them to a new domain? ie I have 2 web domains which will be running classifieds theme and I have almost finished building one; but rather than start from scratch on the other it would be faster to copy my work across and make changes.

Thanks for any help …