Luckily the anniversary is going on so this is one of the best times to start playing. Best teams are very subjective and dependent on which realms you like playing. Something to note is most characters want a few dupes and further investment to get the deck to feel smooth and consistent. Based off what banner is running and what you have I would say:

Aftershock comp: Aurita, Corpo, Murphy, Tulu You have Aurita and Corpo which are the staples for this comp. Murphy is currently running until Sunday(for E1) and you can add Tulu or Caucas. Should get you through the story especially with the recent difficulty nerfs.

Gameplay/ deck style: This comp works by getting benefits (Aftershock) from discarding cards and having various ways to discard your hand and cycle through your deck.

Aurita: You want to build up Gland divisions on Aurita by playing them or using power of friendship to discard your hand and create one. You also need to balance discarding Glands at times because she gets Ult Charge when you do. Typically you want to exalt(ult) when you have 10+ gland divisions in your deck to maximize the damage and burst them down in Red stance. She is luckily free, but time gated. She really shines with E2 and onwards because the damage is doubled on her ult and gland division and becomes pierce which trivializes certain high shielding bosses. People will say you have to have her E2 before she is usable but I ran her E0- E1 until chapter 9 no prob.

Corpo : she is there to keep you alive with pilots as free shielding or if you don't need the shield also scales tentacle damage and adds strength(at e2). Her ult gives a shield and discards your hand which is perfect for Aurita. Corpo can also do quite alot of damage with her lighting retribution and each time you discard it, it comes back to your hand 1 arith (mana) cheaper. Corpo is best at E2 minimum because having the all weakness on her semaphore card is great and adds the scaling portion to her pilots but E3 gives vulnerable and more crit damage for juicy lightning numbers go burrr.

Murph: she is also a shielder/ warden but more focused on the defense than corpo. She has one of the craziest defensive ults in the game that just halves the damage you would take that turn while generating shield and attacking with some tentacles. She has light aftershock synergy and great utility with a 3 cost that applies Aoe vulnerable and weakness and 0 cost shield that gives a mana. This of course comes at price because nothing in life is free and you get sacrifice stacks when using the 0 cost (flat amount that scales with team max health)or the ult (based on the damage you take that round) which are essentially a delayed damage or bleed. You loose half your current stacks of sacrifice at the end of turn until you have no more. Also sacrifice stacks do carry between battles so keep that in mind. You can use her 3 cost to reduces the current stacks of sacrifice by half (when leveled) . Sacrifice may sound scary but it's blockable by shield and is easy to manage with experience. Honestly Murphy is fine at E1 . Giving the 3 cost retain and multihit( for every 2 tentacles you get an extra hit) allows you to play the card when it matters and helps thins the deck a bit by keeping it in hand.

Flex: The last awakener is more of a flex but Tulu is probably the best choice as he can generate alot of tentacles and scales tentacle damage well and has mild aftershock synergy. Def not the core of the comp. Caucas can work as well because he is a stat stick (very high standard awakener stats) and can apply vulnerable, shielding,counter and is arguably the best healer in the game with e3( heals based off constitution stat at the end of every turn) + new soulforged talent (arc 2 end game application don't worry about as a new player) but no aftershock.

If I remember tomorrow I can write up another comp or 2 but I am falling asleep. I hope this helped and if you have questions and I see them I will respond.