This should help with character builds:
https://docs.google.com/spreadsheets...pQFl1/pubhtml#
If i were you, i would lvl Noelle (for shield), Diona (same + buffs), Barbara or Bennet for healing (bennet cant heal fully) 1.st so you have 2 basic things to survive in inazuma.
1.st Garbage bin = Kaeya, Lisa, Razor (phy damage is mostly usless), Traveler, Amber and Thoma (usless with c0 as he will suffer energy reg to keep shield up at all).
There are a few teams that you can build:
Yae Miko (if you have any good 4 star event weapons use those) + Barbara (Prototype amber) + Fischl (battery for miko with any bow) or beidou for shield + Diona (for elemental mastery)
Albedo + Noelle + Ningguang + Bennet (3x geo will give you a lot of power to battery geo characters and bennet is there for just a buff)
Xiangling + Bennet + Keqing + Barbara can make a kinda national team (tho reactions are not the best, but if you can get Yelan it would be realy good).
Sucrose + Fischl + Barbara + Xiangling can make a poors man sukokomon or whatever its called
Yanfei + Beidou + Fischl + Barbara makes a pretty good overload team as Beidou Q helps bouth Barbara or Yanfei to amplifly reactions.
Anyway, your top priority is to lvl up your units to at least lvl 60. (for a team)
Then lvl up their talents and visit some domains to get artifacts (lvl 16 max artifacts are fine for now for specific set bonus). Just be sure main stats and substats work with characters.
Since reshin is a issue, you will have to mine every 3 days and farm crap artifacts in world every day to max the xp gain on those.
If you have problems with weekly bosses or domains, use the group finder and get boosted.
I also recomend you max your serenia pot in meentine if you havent as you can buy xp books and speed up your progress + save reshin that way.