How long would it take to make your one arm as coordinated as the other dominate one

i would like to be mentally balanced and embrace my mental potential. i would like to know other ways in improving my brain activity.

That's an interesting question. I would bet that it would be different for every one.
I say that because when my right arm was in a sling I found out that I was so not left handed. I struggled along for a few weeks and I was just as clumsy and uncomfortable with my left hand when I tried to sign my name, let alone write a paragraph.
And, alas, some people are essentially born ambidextrous.