Lessons are posted in this forum section: http://www.newduelacademy.net/c10-nda-classes
To get points you can do one of the following : duel someone for points in the Duel Arena or the Shadow games arena , Invite someone to the academy and when they join you get +200 DP , win tournaments and/or competitions or you can sell decks/GFX works if you have a shop. You can use these points to request a test/retest , buy decks from deck shops , buy GFX works from GFX shops and more.
I hope I helped. If you have any other questions , just ask a staff member.