Figma is now free for all US K-12 school students
Educators can sign up for access through Figma's website..
If I could recommend them anything it'd be to skip Figma and use penpot instead. Same features and everything, but open-source and no lock-in ecosystem.
Having used both, Penpot still had a feature gap. For example, prototyping in Figma is much farther along. Penpot is still stuck in Invision land.