Nice sentence! It is correct and sounds friendly.
What it means:
- Let's is a short way to say "let us" — it means "we will" or "let's do this together."
- The sentence says: "We will play and learn about animals."
Small improvements you can try (all are okay):
- Let's play and explore animals! (original — good)
- Let's play and explore the animals! (use this if you mean certain animals)
- Let's play and learn about animals! (if you want to say you will learn)
- Let's play with animals! (if you mean playing together with animals)
Punctuation:
- The exclamation mark (!) is fine — it makes the sentence excited and fun.
Fun ideas to do with this sentence:
- Draw your favorite animal.
- Make animal sounds and guess which animal it is.
- Read a book about animals or visit a zoo or park.
Great job! If you want, tell me another sentence and I will check it too.