Did the Greek heroes really lived?

The short answer; we don't know. We have no archeological artifacts dating from the age of heroes describing them as real people. But it is plausible that these people existed, albeit not the demigods mythology makes of them. The lands they ruled certainly existed, and the genealogies presented are logically consistent. Because the region fell into a dark age not that long after the events of the Iliad and Odyssey, a lot of information was lost. Only oral traditions handed down the stories until literacy became common again, and during that time the stories were "polished".

Unfortunately, short of a miraculous archeological find, we will never know how much is fact, and how much is fiction.

Some "heroes" such as Achilles or Odysseus truly lived. Achilles wasn't a semi gOD of course, but he fought and died at the War of Troy. Other heroes like Hercules didnt live in real life. In other epics though such as "Helen" were true stories but hey were changed to make the audience like it more

Depends on what heroes you are talking about. Heroes like Hercules and Perseus? No. Heroes like Leonidas and Alexander the Great? Definitely.

It's "did they really LIVE," not "did they really LIVED." Please, learn how to talk like somebody who's more than 3 years old.