breastfeeding

for the moms who have expirienced breastfeeding, i have questions; 
1. when do I start? 
2. do i really need a pump? 
& this is my concerned one; if I breastfeed at the hospital, i know my MIL & my husbands brothers and sisters will go visit, but if they happen to be there while breastfeeding, do I have to breastfeed in front of them?? i personally do not want to!! i would rather have them out the room or something.