How much alcohol can you have when breastfeeding ?

Ok y'all I am not a drinker what so ever ! I have never ever been drunk in my life. When I have a drink it's literally one Smirnoff and that's it and just one night I don't have anything else any other time the last time I put a drink to my lips was 2 years ago! But I really wanna try a margarita at the beach this year and I will be breast feeding ! I am due today(still no baby) I am going to the beach aug 6-13 is it safe to have any at all??? And how much intake ?? Please NO BASHING.