What difference between "in", "on" and "at" ?

Saturday - 05/21/2016 Hey guys, whats up? Today I'm so happy, cuz I learn things about my family. So let's go, I'm twenty-one years old and I live with my mother and my father and my two brothers in Brazil. I have one grandmother, my others grandparents are dead. I've many uncles and many cousins. For now, that's it ! Have a nice weekend everyone. Se you !

Sunday - 05/15/2016 Haha, hi everyone, how are you? Today was a day very bored, cuz I didn't almost anything. I wanted to go to church, but my daddy was taking my grandmommy at the hospital, so I didn't go to church. Tomorrow I'm back here. See you!

Daily Hi guys. Wha's up? I'm bored. I go talk here now. I'm listening song, love it and I'm already should be seleeping, but I'm here haha

Wpp group Someone has a whatsapp group for practice english ?

Today Hey everyone, how are you? Today in Brazil to be raining, i don't like of this days, but it's necessary. I'm bored here. Someone to talk? xx

My first time here Hi, what's up? I need learn speak english. I can help you with portuguese. Thanks