Back when i was a believer we were taught that Heaven was a massive city made of gold and jem stones that would sit in the sky over the New Earth after the return of Jesus. Descriptions of it involved streets of gold, green pastures and beautiful landscapes in between the giant mansions God had prepared for his faithful servants. At the very center of the city God was seated on the throne.
Basically Heaven is where the faithful are rewarded. the main problem with this is that the reward is more of a punishment. In Heaven there is no sin, which means that most of the behaviors we enjoy here on Earth aren't present there (gambling, drinking, most forms of sex and violence would be out of the question). This means that your choices for what to do are severely limited, while the time you spend there is infinite. Eternity would quickly grow boring, especially without struggles or goals to strive for.
Imagine for a moment playing a video game with all the cheats enabled, only you still have to be nice to other players and can't do anything wrong... that's what heaven is like, and it goes on FOREVER.
Also there is a lot of worshiping that goes on, according to what I was taught and what many believe, the faithful will worship God without ceasing. Bowing endlessly before the same God that damns people to Hell for eternity, some of those people who are damned are probably your friends or loved ones... but who cares right, after all God is SO GOOD, and that's why he made Hell (sarcasm overload).
If you can call what I was taught as a child a glimpse of Heaven Heaven is something I want NO part in whatsoever as within the first few decades it would become its own Hell. Trying to fill an eternity inevitably leads to failure, especially when your main activities include bowing before the divine dictator who is melting the flesh off your family members and fellow humans and the complete inability to commit sin or even have a sinful thought now and then (imagine your life without fantasies about sex, violence, wealth, power, etc, a world where those thoughts and actions are IMPOSSIBLE, where sadness doesn't exist to balance your joy and loss does not exist to make having things meaningful)