There's no right time. Some people meet someone at 16 and live together until they're 100, still in love.
I met my most recent ex at age 18, stayed with him for 6 years, then split up. I thought he was the one. Now I'm with my partner who I met when I was 27 and I can't imagine my life being any different!
My parents were married for 30 years and then split.
Just because you find someone and think they're 'the one' doesn't mean they are, and doesn't mean it will last. You will find a boyfriend when the time is right, it might last it might not, but the one thing for sure is that there's little point worrying about when is the right time, as you can't force these things, nor predict how the relationship is going to go.