hello, i am a retired school teacher
Nice! So you at the point where a person stops employment completely. 
yep, I reached that age of retirement
Sometimes, a person is not fully retired and they may semi-retire by reducing work hours.
you know i heard about that but was not sure how to go about it
It's an interesting topic nonetheless. Just to educate you, the idea of retirement and its origins was introduced during the late 19th and early 20th centuries.
i thought it would have been around longer
Me too. Personally, I would choose to retire when I am eligible for private or public pension benefits, although some are forced to retire when physical conditions no longer allow them to work.
but I may find a part time job just to keep busy, I do not care for retirement
Nice, I think that's known as pre-tirement which is when individuals decide to put off total retirements by selecting to exist in the workforce.