I don't think you'll get any useful advice here. You should be able to come up with your own idea if you want to be a successful businessman anyway. That's how it works usually. Depending on other people's ideas is not a good way to start things. You'll mostly get generic crap like "start a casino", "start an exchange", "sell stuff" etc.
I agree when it comes to creating online content it should be within your passion so you can sustain it in the long term, starting a website especially if you're going to monetize needs a lot of preparation and goal planning. every niche is competitive now compared to a decade ago, getting a domain is easy but sustaining and marketing its content is hard.
Whatever OP plans to do with his purchased domain I wish him success