For early game, Barbara is pretty much mandatory until you are better adjusted for combat. As a healer, she is integral to keep you alive until you’re better skilled. Until then:
The meta game favors a team set up with a DPS unit (Razor or Yanfei would work for that) a DPS support that can raise the damage if your DPS (Kaeya, Sucrose, Rosaria and Xiangling fit well) and often the other two are various other supports, either for shields (Noelle), buffs and debuffs (none of those) or to apply elements (everyone else you have).
From there, you should decide which reactions you should favor. Pyro/Electro makes “overloaded” which is typically considered the best effect, as it deals a pretty huge amount of damage in an AOE explosion. Razor and Xiangling can be a pretty great combo for that one, so you would probably have her either use Guoba or her pyronado to leave a constant flow of fire for Razor to use his electro attacks on between his physical attacks. Adding a cryo would also allow Razor to inflict “super conduct” and lower the physical defense of enemies for a short time, making Rosaira or Chongyun helpful for this (depending on playstyle, Chongyun may be better so Razor can use his ice when waiting for his own burst to charge). If using Xiangling, Sucrose would be a great addition so that her own skills and burst can help spread Guoba’s fire more easily, as he is fairly innacurate on his own. If not using Sucrose, Noelle may be the next better choice, as her shields can reduce damage you take as well as heal you.
So ultimately, I’m advising Razor, Xiangling, Chongyun and either Sucrose or Noelle, depending on personal playstyle. To use this team, begin as Razor to hit enemies with electro, have chongyun place his field down so everyone is hit with superconduct, use Xiangling to place Guoba then switch to Sucrose to create a pyro swirl with her skill or burst over a large area before switching back again to Razor to start dealing damage with more electro and physical/cryo (with Chongyun’s field down). Alternatively, all of the same with a Noelle instead of Sucrose, but without adding the swirl portion and just switching to Noelle now and then to activate her shield or to heal.