The recommended party level is the same as your target enemy level after ascension (35/60/80/90). While not necessary, it is recommended that your team consists of a pyro character, an anemo character, a hydro character, and a cryo character.
Don’t forget about the wooden boxes and barrels. Those may contain ingredients for cooking later. Focus on the Mitachurl as it can be difficult to defeat. Use Pyro to break its shield then use Anemo to spread the effect to the Mitachurl and the Hilichurls.
If you accumulated a lot of Adventure EXP, your World Level may increase by 2.