There are two things you could mean when you say age appropriate.

Are you asking what should they be learning at that age?

Or what content and material is appropriate for children of that age?

If the second it should be obvious, don't show gore or sex.

But I assume you mean the first, in which case nothing is inappropriate. A 65 year old man can be learning his ABCs while a 4th grader is learning essay style writing. Age means little.

And on that, there is no way anyone here can tell you what your students should be learning. You could be Seoul or in a rural location for all we know. You will just have to ask your CTs what the students are learning, look at their books, talk to them and self assess.

Another good resource is this site. There are boards dedicated to elementary level of English. Head over there to get some ideas and get you started on what you should be doing.

I have a feeling you are not yet teaching and are instead in the middle of the interview process, and one step is to write a lesson plan.

If I am correct then a few tips.

Start from the end. Decide what it is you want your students to know by the end of the lesson, make that your students goal, often called a Learning Target. And then go back to the beginning creating steps and tasks to take your students to that goal.

Choose a format, there are many. A popular one among NESes is called 'PPP". I have no idea what this is, but will give you something to research. I use a simple 4 step format.

1. Lesson - teach the target language/skill/etc.
2. Example - provide them with examples and non-examples to help demonstrate what good looks like
3a. Practice - Let the students practice the skills and material taught
3b. Feedback - Provide students with feedback and let them practice some more
4. Assess - Test

You can of course use this format multiple times in one lesson, or spread the phases across multiple days. The point is to never make them practice something you never taught.

Try your best to plan out how long each phase/step will take. This is hard for an inexperienced teacher. You will get it wrong, and that's okay, you need to practice and you will get better at it. Just keep trying, and don't worry about time too much, but it is good to include in your lesson plan.

In your lesson plan always plan for what materials you will need. i.e. computer, white board, work sheets, Co-teacher, wide open space, etc.

The focus of the majority of the lesson should be on the students. Do not have the focus on the teacher (which completely goes against Asia's style of teaching, but is what EPIK is looking for and what you should be aiming for). You have to cut down teacher talk time to a minimum.

Because your students are so young, things like writing are not super important. You really want to get them, excited, learning, and practicing (speaking). I say focus on Speaking a listening the most, and then reading second, with writing at the end of the priority list. But that's my opinion.