Youāre absolutely fine to drink afterwards if you want to. I knew absolutely zero about aftercare when I got my first one done (started freaking out completely when the dead skin/ink started coming off, as even the tattooer didnāt tell me that that would happen) so I bet youāll be more than fine. Just ask your tattooer what they recommend. (I also recommend Bepanthen as @83746725 mentions).
My top tip is to just sit as still as possible. Most of the people who have tattooed me think I sit almost too still but Iām just so afraid Iāll suddenly move my arm/leg whatever if the needle hits a nerve or whatever, and Iāll ruin the whole thing. The actual tattoo artists seem less concerned with this than I do though, so what do I know.
In summary: Youāll be fine, donāt worry.