Prayer is a conversation between friends- God with his creatures. There really can be no set limit on how long we should pray, since we should pray throughout the day. We can talk to God freely when we have a difficulty, we should thank Him when we rise and when He helps resolve our daily trials for us. We should talk to Him and tell Him what’s on our mind often, just like you would to a friend. He’s always there for us as a friend.
Instead of thinking about whether or not 10 minutes is enough, why don’t you think of “If my best friend were always by my side, how often would I talk to Him?” or “If my spouse were here, how much conversation would be enough?”
The answer is none, since we owe all our time to God.

You obviously wouldn’t be constantly talking to your friend, but you might say something every now and then to them, right?
One thing that helps to keep your mind focused on God is to just say something to Him every now and then throughout the day… When you have a break from work or when you’re tired, just say “Jesus, I love you” or “My God, how I love Thee!” or “God, how great you are!” or “Mary, Mother, how beautiful you are!”. Talking is God= talking to Jesus

Don’t worry. Just start talking, like you would to a friend.