praying & everything below

Earlier today my grandmother asked me about my thought on prayer and i had a huge difficulty answering her question. Eventually i just told her that i didn't know and that i had no real thought on praying. It's not that i did not know nor that i did not have a thought on it. It's that i feel as though i may not pray properly. I pray for people when they are sick, in pain, etc, but otherwise i have troubles talking to God. I also feel as though my prayers in a way are selfish because in a weird sense, i benefit from people's happiness. Oddly it makes me warm to see others happy, but also makes me cry to see others sad. Funny thing is it's easier for me to cry for others than it is for me to cry for myself. Obviously i am not perfect because i have to build a relationship with God when i'm mentally matured enough for it, become a balance of selfish& selfless, but also figure out what makes me selfless. Basically, i need to get it together and understand praying and everything below.