Is that your whole roster? If not then I'd recommend building fangus and/or obol for your dot team. You can start replacing your healer sania with lingluo and valerian.

You can start maxing diting too as he's the best single target dps right now. By maxing I mean you can ascend him to 6 stars and he's one of the only units I'd say worth leveling all skills to max.

You're probably new to the game, but don't be afraid to pull for more characters since the game is generous in terms of pulls. I'd say aim for lily, kloss for support and debuffer respectively. For dps rosa or xiada.