Everyone does not go to heaven eventually, especially Satan. Only those people will serve their time in hell and then go to heaven are the ones who did not commit any major sin (ie blasphemy), for which punishment is eternity in hellfire. These people are (temporarily) in hellfire because they did more bad deeds (sins) than good deeds, but they did not commit any major sin. There is no serving time in Hell, there is only non-stop constant punishment. A person can always repent, and a sincere repentance can be rewarded by Allah turning all of your bad deeds into good deeds. A sincere repentance involves remorse over the sin, abandoning the sin, absolve not to do it again, and attempts to make amends.
WHOM ALLAH FORGIVES
Verily! Allah forgives not (the sin of) setting up partners in worship with Him, but He forgives whom he pleases sins other than that, and whoever sets up partners in worship with Allah, has indeed strayed far away. (Quran 4:1116)
WHO WILL GO TO HEAVEN
Allah has promised to the believers -men and women, - Gardens under which rivers flow to dwell therein forever, and beautiful mansions in Gardens of 'Adn (Eden Paradise). But the greatest bliss is the Good Pleasure of Allah. That is the supreme success. (Quran 9:72)
These are the limits [set by] Allah, and whoever obeys Allah and His Messenger will be admitted by Him to gardens [in Paradise] under which rivers flow, abiding eternally therein; and that is the great attainment. (Quran 4:13)
WHO WILL GO TO HELL
"Allâh forgives not that partners should be set up with Him, but He forgives anything else, to whom He pleases." (4:48)
"Say: O My Slaves who have transgressed against themselves [by committing evil deeds and sins]! Despair not of the Mercy of Allâh, verily Allâh forgives all sins. Truly He is Oft-forgiving, All-Merciful". (39:53)
WHO WILL BE SAVED FROM HELL
"...When Allâh (swt) has finished judging mankind, and wants to bring whomever He wills out of Hell by His Mercy, He will order angels to bring forth those upon who He wishes to bestow His mercy of the people who never associated anything in worship with Allâh (swt), and who said, "Lâ ilâha illâh Allâh". The angels will recognise them in Hell, and will known them by the mark of sujûd on their foreheads. The Fire will consume all of a man except the mark of sujûd which Allâh (swt) has forbidden the Fire to consume. They will be brought forth, having been burned in the Fire, the water of life will be poured on then, and they will grow like seeds left by still after a flood". [Sahîh Muslim, Kitâb al-Imân, Bâb ar-Ru'yah, 1/299, no. 182]
"Allâh (swt) will admit the people of Paradise to Paradise and He will admit whomsoever He will by His Mercy. And He will admit the people of Hell to Hell, then He will say, "Look for anyone who has the weight of a mustard seed of faith in his heart, and bring him out"". [Sahîh Muslim, Kitâb al-Imân, Bâb Ithbat ash-Shafa'ah wa Ikhrâj al-Muwwahhadîn, 1/172]
"Whoever says Lâ ilâha illâ Allâh and has a barely grain's weight of goodness in his heart will be brought out of the Fire. Then whoever says, "Lâ ilâha illâ Allâh" and has a wheat grains weight of goodness in his heart will be brought out of the Fire. Then whoever says, Lâ Ilâha illâ Allâh and has an atom's-weight of goodness in his heart will be brought out of the Fire". [Sahîh Muslim, Kitâb al-Imân, Bâb adna Ahl al-Jannah Manzilatan, 1/182]
LAST PERSON TO LEAVE HELL & ENTER HEAVEN
"The Messenger of Allâh (saw) said, "I know the last of the people of Hell who will be brought forth from it, and the last of the people of Paradise to enter it. It is a man who will come out of Hell crawling on all fours." Allâh will say to him, "Go and enter Paradise".
So he will come to it and will suppose that it is full. He will go back and say, "My Rabb, I found it full". Allâh (swt) will say, "Go and enter Paradise for there you have something like the world and ten times over [or you have something ten times better than the world].
He will says, "Are you making fun of me - or laughing at me - and You are the Sovereign of all?" I ['Abdullâh] saw the Messenger of Allâh (saw) smiling so broadly that his back teeth were visible. He used to say, "That is the one who is lowest in status of the people of Paradise".