Are you in Middle-Earth? Based on the text, I'm assuming the answer is "no". I'm not sure if this is the correct place to ask this question, but I'll answer it nonetheless:

Diamonds spawn very deep, at level Y15 usually (you can find this value under "coordinates" by pressing F3). And they are more likely (at least, in my experience) to soawn in these very same monster-filled caves (at the very least, you'll have an easier starting area to search).

I suggest you armour up fully in Iron before searching. Remember to being an Iron Pickaxe, as its one of the only ways to mine diamonds!

Here's a guide that might explain it better:

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.ign.com/wikis/minecraft/How_to_Find_Diamonds&ved=2ahUKEwicmMjr28vzAhVaiFwKHbvzBCkQFnoECC8QAQ&usg=AOvVaw1yQ9Ac1CpQp-OmLJPT11ae