In the US we designate “liberal” and “conservative” as two sides in a spectrum dealing with civil liberties issues.

Liberal means left wing, correct?

Yes the liberal side is considered “left” and the conservative side “right.” Liberals lean more towards freedom in civil liberties as well as equal rights regardless of race, religion, gender, nationality, class, etc. Conservatives lean more towards a traditional view on civil liberties, traditional home structure, strong sense of nationalism and individual property, adherence to morals based on tradition, etc.

For example, it is correct to say "Cuba, North Korea and China are among the most liberal countries in the world".

No, that’s not correct; not in the way we use the term anyway. I'm not sure if Spain would consider them the most liberal countries in the world though.

“The left” we refer to would not be considered similar to the examples you gave considering it’s a label we attribute to civil liberties issues and I’m quite sure that US liberals wouldn’t support the same stringent policies that restrict civil liberties in the governments of the examples you mentioned.

I suppose Americans use the term liberal so that they don't get called commis.

There has been strong bias towards communism since the Cold War Era leading to many misconceptions over time, many of which are still popular today. As an economic system I think US liberals/ democrats (the left) would support communism under the same principles of socialism, but as a government, it would probably be met with opposition from both sides of the spectrum.

Being prochoice is not just about abortion. People often have dif ways on being prochoice but every prochoice liberal I have met so far has supported contraceptive coverage. Can you please tell me how it makes sense to be prochoice and not support contraceptive coverage? It seems contradictory.