Honoring his life

My nephew just died of cancer he was 8 years old😭😭😭😭

And we can’t go back to Mexico because we are stuck here because of our visa situation but we feel like we need to do something to honour his life we are thinking doing something in a church but what else do you recommend and also

We don’t know how to tell our kids they are 4 and 2

Please we are devastated don’t know what to do