How do I deal with feeding and a busy schedule?

I have oreintation for college 4 weeks after my baby will be born. I need advice on what to do about feeding during the two day period I will be there. I can not nurse during cl. Will missing a few feedings in two days affect my supply enough that I can't nurse anymore? How often should I pump? I am very nervous about this and need as much advice as I can get.