experts on breastfeeding

Ivy • Blunt. No sugar coating cause it'll rot u 😜
If I had coffee this morning how long should I wait before breast feeding ?
Also I don't have a breast pump yet, which is why I'm asking.. 
I also take medication, Pharmacist said to pump out that milk first, before feeding her.. how much am I suppose to pump out ?
I'm new at this , I need all the help I can get