New to Ravencoin mining.

Hello all, I was mining ETH till yesterday and today I’ve decided to give RVN a try. And there are few new things that I don’t understand, could someone help me out? Is RVN hash always half the hash that we get for ETH? What is immature balance? Till now my immature balance is more than 3 and unpaid balance is only 0.07. Currently mining at 77mh/s so how long will this take to reach the 10RVN threshold? I’m using ethermines flypool server. Since I used to mine at ethermine I preferred this. Can someone suggest a better mining pool as well? Thanks for the help in advance.