Just going to add that you can also use commands or external tools to locate structures. Some people would consider it cheating, but imo, as someone who has played the game for a long time, I think there are times where using such tools can make the game more fun (which is the goal of a game). It can be fun to just explore around, but it can be frustrating not finding what you are looking for.
If you are an operator on the server, you can use /seed, which will give you the world seed that you can copy by clicking the text in chat. Put that seed, when prompted, in to www.chunkbase.com/apps/ and it will tell you the coordinates of the structure you wish to find.
Of course, I’m only mentioning these as options. It’s up to you what you think would be most fun for you and your kid. Just walking out in to the wilderness can also be fun (remember, your spawn is usually within 100 block range of coords 0 64 0, so you can use that to get home). Others have suggested cartographers; if you need Emeralds selling a Farmer his own wheat (from village hay-bales) can help.