Hello mummies out there~ anyone knows more about breastfeeding? Don't mind sharing with me~ I'm a…

Hello mummies out there~ anyone knows more about breastfeeding? Don't mind sharing with me~ I'm a first time mom and only 21 years old so there's stil a lot that I don't know about breastfeeding~ will appreciate if mummies can answer to my questions below :) thank you!

1) how do you know baby is drinking milk instead of latching for comfort? Yesterday my 9 days old baby latched for 40 mins and she went to sleep. Then 30 mins later she woke up again and I tried giving her formula and she drank all 60ML~

2) how do you increase the flow of your milk?

3) how do you know if baby drank enough? Most of the time when I latch her, she will stop halfway. Sometimes is asleep sometimes she let go on her own. Then I'll put her down on her bed, she will cry after a while and when I tried latching her again, she'll drink. This confused me~

4) will she spit out her pacifier if she's hungry so that she can latch? Or will she continue sucking her pacifier?