Generated new cryptocoin but how to get balance in my account?
Coins that are immature mean that you have not mined enough blocks for them to be spendable yet. If you did not change the COINBASE_MATURITY global variable, then you will need to mine 100 blocks before the immature coins become mature and spendable. Of course the process of mining produces new coins, so your immature balance will increase until you have mined 100 blocks.