You have some awesome characters only being 1 month in. Diluc is S tier. Mona is S Tier. Ganyu is SS tier.
Diluc/Ganyu will be your main dps prob for a very very long time. I really really don't recommend them on the same team.
Note* a lot of these suggestions/teamcomps will be abyss based. For overworld just have fun with it and play what you like.
Teams:
Diluc, Xinqiu, Bennett,
- I'd recommend focusing on Sucrose and Mona. Sucrose eventually for abyss (aoe vaccum) unless you get Venti. Mona for burst
Ganyu, Diona, Fischl,
-Ganyu Diona will give your Ganyu tons of crit due to ice elemental resonance (15% more crit).
-Fischl is just a great support to have. Oz is really strong.
-Since Ganyu is SS tier you don't necessarily need a 4th. I'd slot maybe xiangling.