The licensing terms for assets on Mixkit are clear. You can download videos and audio files from Mixkit to re-use and remix. You don't have to credit Mixkit, but they will appreciate it if you do credit them.
Applications for EducationMixkit is a good resource to bookmark and share with your students when they need music, sound effects, or b-roll videos to use in their own video projects, podcasts, or other multimedia presentations. If you're worried about your students wasting time browsing through the Mixkit galleries, create a shared Google Drive or One Drive folder that you add a collection of Mixkit files to for your students to use.