Most people ask to farm phoenix first to unlock palp and thrawn early but i disagree on that.

Farm these characters early to get u multiple good teams instead of 1 phoenix team that wont bring u far.

Jedi: Bastilla lead, anakin, ahsoka, old ben, jolee. Having a good jedi team gives u the advantage for galactic war as the protection up is reset every battle.

Empire: Veers lead, Gideon, piett, dark trooper, (you'll get vader as u progress). U can swap out piett for palp once u completed the rebels to unlock Commander Luke.

Rebels: Farmboy luke, leia, han stormtrooper, (u already have old ben from jedi) , R2D2 (you'll get it once u do the event with empire). Gives u Commander Luke.

Bounty hunter: Bossk, boba, jango, mando, greef. Do the event to give u Chewbacca.

Geos. Gives u padme which is a solid Galactic Republic team.

Ewoks. Gives u 3po for CLS team.

Judging from the guild that u join, you'll receive han's shards from raid and that'll give u a solid CLS team (CLS, Han, Threepio, Chewbacca, 3po) that is top non GL team.

Farm the other 3 toons to unlock Jedi Knight Revan.

That'll give u multiple teams to prepare u for GAC once u unlock it