I would say what my dad always said to me when I was about to try something new: "Have a go, Joe". Even now, in my 70s I can hear his voice encouraging me when I want to try something new.
I would also add: "You have the freedom to fail, so when/if that happens, pick yourself up and carry on with life." I can still hear the critical voices of other family members telling me that my best isn't good enough! But I have learned - eventually - to disregard them and listen to my dad!
But I wouldn't have understood what I was saying to me, and filed it under "grown-ups' talk".
Sadly, I didn't hear properly what my dad was saying until around the time I left home for university, but I always heard clearly what the critical ones were saying!
We tried to bring our children up to listen to encouragement, and we can see how they are encouraging their children in turn. Hopefully, the destructive cycle is broken.