Student names can be ordered by first/last or last/first. This can be determined in two places: "Naming Conventions" on the Settings page (for all users) or on an individual user's setting page. See here for more on sitewide naming conventions.
An individual user's setting takes precedence over the sitewide setting. In other words, if you've never set your preference for first/last or last/first, you will view names according to the sitewide setting. However, if you prefer to view names differently than you do now, you can visit your personal settings page to change things. Access your personal setting by clicking on your user icon in the upper-right and selecting "Settings".