What do you think about me being engaged after a year?
Why did you decide now was a good time to get engaged?
We got engaged so we can start a family and we both don't wanna waste time
Well, as long as you're sure this person is the one for you there's nothing wrong with getting engaged after being together a year.  Waiting on an engagement for no reason but to wait is a bad way to go about it.
I get engaged so I can pick the right person I want to marry
That's good. you want to make sure you are marrying the person that is right for you and who you love.