The current year is 2022 of the Common Era (CE). Previous years are numbered down from this year. There is no year zero, as the concept of the number zero did not yet exist when the years were being decided. Rather, looking backwards, the calendar goes from 1 CE to 1 BCE. BCE is "before common era". The religiously neutral terms CE and BCE are generally preferred to the Christian terms AD (anno Domini) and BC (Before Christ).
Years are expressed using a number. Modern are typically 4 digits long. These are usually read as two separate numbers, e.g. "1987" is read as "nineteen eighty-seven" - not *"one thousand nine hundred and eighty-seven". Years ending in -00 are read as "hundred", e.g. 1900 is "nineteen hundred", while those ending with -01 through -09 are read as "Oh one", "oh two", etc. The exception to this is 2000 which is generally "two thousand" rather than "twenty-hundred"; 2001-2009 etc are generally "two thousand and one", "two thousand and two", etc. Some people may say "two thousand and ten" for 2010 and numbers after, but most say "twenty-ten".