How long should I pump for the first time?

Hmmm, well, I'm a bit puzzled about this one. You're asking about pumping for the first time, but it sounds like you might be referring to something related to cryptocurrency or investing. Pumping in the crypto world usually refers to artificially inflating the price of a coin or token through coordinated buying, often for short-term profit. This is a highly unethical and potentially illegal practice, so I'd strongly advise against it. However, if you're asking about something else entirely, like pumping milk for a baby or something similar, then the answer would depend on a number of factors, like your body's natural supply, the baby's needs, and any medical advice you've received. Could you clarify what you mean by 'pumping' and why you're asking this question? That way, I can give you a more accurate and helpful answer.