Criticism against agnostics and atheists

Hi. I am an 11 year old agnostic who lives in Delaware, US. I have experienced the brutal insults that come with being an agnostic. From my understanding, being an atheist means you have a different religion and agnostic means you believe in evolution. And whether I am wrong or right, I'm pretty sure that criticizing other beliefs is not exactly what the christians aim to do.
Most of the people I have encountered who are unnecessarily rude about my beliefs have been christians, while others leave me alone. Some think its my fault for calling christians out, but I have never done that. It always just comes up in a casual conversation, whether we're chatting about our christmas tree ornaments and someone mentions how much they love god and have an angel at the top of theirs, to whether its their Easter agenda.
I have no problem with others' beliefs, nor should they have a problem with mine. I simply don't think its right that as a 5 year old in kindergarten, my fellow classmates were already telling me that I should go to hell, and that they would exclude me from their lives and shut me out, just because I didn't believe.
I even had one friend, who liked me, but I don't think she knew what to think of me. One morning she would tell me how she wanted us to be besties forever, and the next she would ignore me and say she didn't like me because I didn't believe in God'. Attending an episcopalian school, I was bound to run into some religiousness. But I was attending the school for their education, not to because of religious purposes. Before, as an ambitious grade schooler, and still admittedly so, I realize how wrong that was. I wasn't a bad kid, and although immature at times, as small children tend to be, I was the one who was reading novellas while others were reading comic books. Researching the Egyptians while others were skimming over fashion and sports magazine. I was endlessly curious, and even broke the rules from time to time to further my curiosity. I never really bothered anyone, and all I ask is the same for others.