What age is it when you actually can drink a beer like a normal drink without feeling a little sick at?

It doesn't depend on age really. It's an acquired taste, just like coffee or mushrooms or any other of the few food/drink items that are most commonly disliked.

It's tolerance and experience more than age.

It's not a question of age but of experience. Just keep drinking beer and you'll get to enjoy it.

Anyone can enjoy a beer without feeling sick, unless they have a health problem which causes them to not respond well to alcohol consumption.

There's no set age for this. Some people can never drink beer because of health reasons. Celiacs are like this.

any age someone who likes to drink beer can do it without being sick!!!