alcohol question?

My husband and I are going out for St Pattys day and I have a four month old that I am breastfeeding. I've never drank before while breastfeeding but I want to know how much is usually a safe amount. I have no intentions of getting wasted at all. I went from pregnant and breastfeeding my older daughter to being pregnant and breastfeeding again so I know my tolerance is shot. I also don't know if I should bring a hand pump or something lol. I want to go out and have a good time, but this seems like so much work 😂 I'm kind of having a panic attack lol.