The term Qadr means the divine destiny that everything is planned but you can also change your destiny. Qadr (Arab., qadara, 'has strength for, gain mastery over'); it is the decree of Allah which, in Muslim belief. If we fail to believe in this pillar of Islam, we are not completing our faith. This can result in leading astray and also believing in the wrong things. However if we later on start to believe in Qadr Allah (SW) is merciful and forgiving and will forgive us Inshallah.
Believing in Qadr does not mean that believes do not have freewill this is false believing still have freewill.
Qadr in real life is as such a hadeeth of Jabir 'No slave of Allah will truly believe until he believes in Al Qadr its good and bad from Allah, until he knows that what has happened him was not going to miss him and that what missed him was not going to happened him.' [Tirmidhi] Belief in al-qadar (the Divine decree) is the sixth pillar of faith, and no one’s faith is whole deprived of it. It is told by Ibn ‘Umar (may Allah be pleased with him) heard that some people were denying al-qadar. He said: “If I meet these people I will tell them that I have
zero to do with them and they have zero to do with me. By the One by Whom ‘Abd-Allah ibn ‘Umar swore, if one of them had gold equal to Mount Uhud and he spent it, Allah would not accept it from him unless he believed in al-qadar.” [Saheeh Muslim]
As Muslims, we have a duty towards Qadr and they are very simple. We should accept the Qadr along with the destiny that Allah has given us. And we should always be making dua that our Qadr is good Inshallah!