in the United Kingdom you can drink from the age of 4 if you have parental permission and are in your own home
In America it depends on the state when the laws are, but most you have to be 21 to buy it. Most kids that get alcohol underage have friends older relatives or even their own parents buy if for them. But you can get ticketed and fined for underage drinking as well as the adult can go to jail for supplying to a minor, so- better think it through.
you must be 21 to drink alcohol
yes
underage drinking
Is possession of alcohol considered a felony or misdemeanor?
No it is not legal.
No
In most states, a underage person cannot be at a party where alcohol is being served. This goes for anyone who is drinking or not.
Maybe you like the taste, but can't drink alcohol. (underage, pregnant)
No it is a misdemeanor in the state of Mississippi.
No, you can be charged with underage use.
No.
Nope, Alcohol only affects you if you're over 18 (or 21 in some jurisdictions).