Enroll in your first track
Open Classroom. Click the Catalog tab. You'll see every available LearningTrack — filter by subject (Algebra, Civics, Maritime, …) or grade band (Elementary, Middle, High, Vocational).
Click any track to see its lessons, the "why this matters" framing, and the practice modules each lesson opens into. Click Enroll to add it to your My Tracks.
You can enroll in as many tracks as you want — they run in parallel, like classes at school. Your progress lives on your account forever, regardless of which org you're working in or whether you change schools.