Hi Jessica,
We have a lot of plugins already installed.
Moodle for Free sites are designed to be easy to use, and come with the standard MoodleCloud theme More. Your site is preconfigured with the plugins that are made available in the standard Moodle version. Also included is an integrated the open source web conferencing System, BigBlueButton.
Starter sites include the same plugins as Moodle for Free sites and also come with the popular and very useful Custom Certificate plugin allowing you to reward students with certificates through your courses.
Moodle for School sites come with the most popular and Moodle plugins, that will cover the needs of most Educators. The current list of provided plugins is available at https://moodle.com/cloud/school. Keep an eye on the list as it will grow, and we always appreciate feedback and suggestions, so let us know if you think a certain plugin would benefit Moodle for School users.
If you require specific plugins for your Moodle site, contact one of our Moodle Partners to discuss your custom hosting needs.
Many thanks.