Planning on drinking for “properly” on 2 days

Hi! Im 21 and fairly average on both weight and height , I’ve drinked before but it was always more on the lesser mount, however this Wednesday I got a 40% ALC/VOL Vodka bottle to celebrate with a friend during vacation at my place.

Are there any general advice you’d give to someone drinking for the first time? Amount to drink , amount of pause between each drink, when’s good time to stop etc, anything is appreciated, just better to be safe than sorry especially for a first time