Hi,
First a few things you should know - MoodleCloud extends core Moodle to provide things like BigBlueButton, a new theme and some other optimisations (caching etc) so you wont have a 100% exact mirror but it will be close enough.
You can download Moodle from https://download.moodle.org/
You can perform a Site Export of your MoodleCloud site from the Portal by visiting https://moodlecloud.com and logging in using your site name and admin password, then going to Tools -> Export my site.
You can restore your site export to the database on your home server and with a few minor tweaks of the provided config.php you will be up and running in no time.
If you need help along the way be sure to check https://docs.moodle.org as we cannot provide support for sites hosted off the MoodleCloud platform.