It’s likely not about tennis, unless the CEO is a dick, it’s about an excuse to meet you and evaluate how you are as a human being.

Unless there’s a specific dress code requirement, I’d arrive in comfortable clothes, smart casual, clean and with a smile on my face.

When you’re asked about your lack of racket I’d point out that not only have you never played, you didn’t think it would be prudent to spend money on gear you know nothing about.

Remember, this is about people, not about hitting a tennis ball.