2 month old sleep through the night

How can I get my 2 month old daughter to sleep all night? Lately all I've been hearing is how she should be sleeping through the night & not waking up every 2-3 hours. I don't know what to do. I was told to try rice cereal but she's already been on rice cereal for almost two weeks now (her pediatrician told me to give it to her for her acid reflux)

Any suggestions?

EDIT: not to be rude but like I said I was told by her pediatrician to give her rice cereal I wouldnt just give it to her without permission so please stop with all the it's not good for her stuff. She has really bad acid reflux and it's literally the only thing thats been helping her keep her milk down.