Chocolate milk if you can, good protein and carbs if you're too lazy like me to mix protein shitshakes. My coach is always saying that it's one of the best/laziest/easiest things to get, so yes, milk is pretty decent.

I think so. It has high amounts of protein and calcium.

and how much should I drink daily if you consider that I work out three times a week? I am 1,80metres high and weigh about 72kilograms

For my workout, I usually just drink one glass afterwards. The average cup of milk has 130-140 calories and 10-11 grams of protein, which is pretty good. If you want, you can drink one cup before and one cup after, which gives you about 20 grams of protein and only 250-300 calories. Even on rest days, you should drink milk, the nutrients help repair your muscles, stacked with being rested on an off day. The calcium also helps strengthen bones, too.

In short, it's mostly recommended you drink at least one glass a day.

and does it matter when exactly I drink it? 30mins after workout, or 3 hours, or immediately afterwards? Also, does it matter if I drink it cold or heat it?

Most would recommend to drink it 30 minutes to an hour after working out, to let the body settle down. Whether you drink it hot or cold is up to you. I like to drink it cold, because it helps the body cool down after a hard workout. You could drink it hot if you live in like a really cold area or something though, lol.