Game veterans advice needed

This game is all about the events, which will get you some really good resources as a new player. Assault battles will get you everything you need to relic your characters. Most of them will let you use two different squads, but only one of the squads matters. If I remember right you will want an Imperial Trooper Squad, Empire Squad, Sith Squad, Jedi Squad, Rebel Squad, and Night Sister Squad. Empire, Sith, and Jedi are the most beneficial long-term. Look up what you need for these because beating every level of them requires very specific squads for the most part. 

Along with this, get a scoundrel squad with Han and Chewbacca for their smuggler events. These will get you mod upgrades.

Second Most valuable investment you can make is in one of the Journey fleets either executor, profundity, or leviathan. Profundity is good but its squad members are meh. Executor is the easiest route and has decent heroes for squads, but leviathan is by far the most worthwhile with really good squad members. Executor is crazy long grind though.

Fleet arena gets you crystals for long-term investments and if you have one of those fleets at 7 stars then you will consistently be getting 100/day from being in the top 20.

Rest up is up to you and what interests you. Just try mix in a few powerful characters like Darth Revan, Malak, Jedi Luke, and General Keywalker. Those alone could carry you Through most of the galactic conquest stuff.