Qadha for missed fasts

Q: If I have not kept many fasts without any valid reason in my childhood, when I became baligh how do I fulfill it? Do I have to make kaffara? What is the kaffara and what if the amount of fasts is so many and I don't remember? 

Balance between ibaadah and social life

Q: How do I balance between ibadah and everyday life? When my sisters come they complain that I don't give much time to them.. I also feel it difficult to go to someone else's home and fulfill my regular amal as it takes so much time..I also fear after marriage I will not be able to continue these aamaal as there will be so much responsibilities.. so what should I do?