For your main character, it's generally recommended to save some levels before becoming a Jedi. For example, leveling your starting class (Scout, Scoundrel, Soldier) to level 7 or 8 before becoming a Jedi allows you to gain more feats and skill points from your initial class, which can be beneficial. This is especially true for Scoundrels, who gain Sneak Attack bonuses. However, if you want Force powers sooner, you can switch earlier. Balance early game strength with later game Force power access.
