At your level, just focus on working on kingdom quests and low-level challenges for now. There are some helpful guides, but a lot of new content has been introduced in the last couple weeks so some things will be out of date or irrelevant now.
In general, open chests whenever you get them and try to save any gems you get (your target is one of Celestial or Dragon armor). Also, go ahead and join a guild. You’ll want one with a combination of active players and no requirements. Once you level up a bit more, you can start to contribute to guild tasks, but for now, you want to rely on the kindness of strangers.
I’m sure others will jump in with more advice, but feel free to ask questions and poke around the forums for information. There is a ton here, but you will need to filter a bit since the game is constantly evolving.
Edit to add: Here is an example of a really good intro guide that is a bit out of date. 90% of what is said is still applicable, but things in the videos will look quite different. I rewatched these a few months ago and they were still full of really good information for new players. If anything specific doesn’t make sense, just ask here and one of us can steer you in the right direction.