Diaper and milk powder

Hi mummies, Im at my 23weeks now, and was told to start surveying on which diaper brand / milk powder is better. As ive no clue at all. Honestly i want to breastfeed but i dont even know if i have milk to start with? Hence, i should buy a tin in case right? Any suggestions on which brand is good? My MIL told me that some brands are good for bby IQ/EQ etc... any idea? #1stimemom #firstbaby #advicepls