The resources you need for this will come naturally as you complete the story episodes, but if you are low on bricks i find travelling into the space of regions and going after khyber comets which give 5 at a time(but only spawn once)
As the other guide says focus on one class for this achievement, doesn't matter which(but don't upgrade the core class).
Once you upgrade it to 100% this will unlock the achievement.
You need 96 khyber bricks and 340,000 studs to fully unlock the jedi class