Starting over and unsure

My 12 year old daughter had reflux so bad when she was born that I gave up breastfeeding and put her on a sensitive formula. Being a first time mom I was so nervous that she threw up constantly I did not try very hard to continue breastfeeding or seek advice, we just went through formulas till we found one that did not bother her.

Almost 4 years later her brother was born and latched on within an your of birth and fed every two hours and went right to sleep. And that was great, but I did not pump with him.

8 years later and I'm pregnant again and we are starting over. This time around I very much want to pump so my son and daughter can feed their sibling. So any tips or advice is greatly appreciated. Like should I feed baby and then pump? And is it ok to flip flop from breast to bottle? Ideally I would love for baby to be used to both breast and bottle, however I understand that may be hard. Will a pacifier help with the transition?