When you like someone you know is out of your league, or at least you think they are

They show some interest in you, would you go for it? Or work on improving yourself until you feel like you're able to meet their expectations so you don't go through the shame of being rejected by them?

There's this really attractive woman who invited me out and I've been a bit hesitant because she's suuuuoer attractive and I feel like, I'm not on my best shape right now so I don't wanna ruin my chances with her, maybe at a later time would be best