Help! I need tips for taking care of a 2 month old!?

I'm 16 and I'm starting a babysitting job on thursday that requires me to take care of a 2 month old, 2 year old, and 4 year old. I'm kinda nervous because I havent taken care of a baby in awhile.The two year old is potty training and is a boy. The two month old is also a boy. She said hes not very good at taking bottle because he is being nursed and says he is not a low maintenance baby. It would be super helpful just to get some tips on taking care of babies and how two juggle these 3 adorable kids and how to be the best babysitter I can be :)