Need some advice!

I’ve known this guy my whole life but he’s 6 years older then me but we have been talking for about a month and we click instantly it’s never a dull moment in there. I have liked him since I was younger and I didn’t even know he knew I existed other than he’s my best friends brothers best friend if that makes since. I’m an athlete so he always encourages me with everything I do and he challenges me as well, when should I come out and say something about trying a relationship with him?