Nice sentence! Here are two simple, correct ways to say it:
- If you mean any capybara: "A capybara is friends with everyone. It's not afraid!"
- If you mean one particular capybara: "The capybara is friends with everyone. It's not afraid!"
Why this is easy to read:
- Use two short sentences instead of a semicolon — that makes it clearer for little readers.
- It's (with an apostrophe) is short for "it is," so "It's not afraid" is correct.
- Choose "A" if you talk about any capybara, or "The" if you talk about a specific one.
Good job — your original sentence was almost perfect!