Good afternoon,
you need some teams along the street and you should focus on what is needed the most, a Arena Team and a Fleet Arena Team (If you not spending it´s the best way to earn as many crystals you can get). If you are already in the top 200 of the arena you still have a chance if you see you not have a chance to come easily on higher ranks, you shouldn´t try to hard. with a investment of 200-300 crystals you can easily get your 600 tickets a day.
Dont´buy zetas from the shop, get the ships first you need it for the challenge and in the moment there is no "big difference in the meta".
You should aim for several teams but only have only 1 project at a time. For myself i searched relativly fast for a Guild that´s doing heroic Rancor so you can get Han. Rebels are still versatile in the Raid especially if you have CLS. Mods are Mandatory. You need to find a way to invest your crystals wisely. I am normally farming a toon in cantina and buy some mods each day. I am doing 3 refreshes in the Cantina and usually 2 in the normal holo table.
you should get teams like, Phoenix, Rogue One, they will help you in the Raids (Terretory Battle), You should also get captain Han Solo.
For Rancor i recommend Wedge Lead, biggs, Han Solo (if you have him 7 star), Jyn and also CLS. That gives me always the possibility to solo the rancor. also this teams not need tooooo much gear.
Also you can prepare for darkside first, i am not that experienced in the dark side, but i wouldn´t mix, just focus for one side first.
Also Preparing for the Heroic events of toons like Thrawn, bb-8 and JTR.
I hope that are some informations, that you understand :-)
have a nice evening.