I’m a 45 year old business owner who also has focussed on diversifying my income streams. I have a short term vacation rental in Florida that I bought for $390k in 2012 and net rental income for the last three years has been growing steadily. 2015 I am at $70k gross right now but should end up at $80-85k with net around $45k plus we use the place about 35 nights a year.
Unfortunately, I can’t answer that conclusively one way or the other. It all depends on you, what you like to do, your work ethic, personality, etc. If you are a good writer perhaps you could write a book and make money that way. Or, you could start your own website and do affiliate marketing. Just because you are young it doesn’t mean you can’t make money doing at least a few of these ideas. I wish you luck in your money making efforts!
In 2017, I ended up deploying roughly $611,000 into stocks and $604,327 into municipal bonds. The stock allocation should boost dividend income by about $12,500 a year, and the municipal-bond portion should boost income by about $18,000 a year after tax ($26,000 pre-tax). Therefore, total passive income gets an about $38,500 lift, which recovers over half of my $60,000 loss from selling the house.
Generating passive income requires upfront work. Some say achieving passive income is actually quite an active pursuit. Some paths may be. But then they may not be truly passive income investments. Acquiring a passive income producing investment can be very simple, even if there are many others behind the scenes doing a lot of work to vet, package, and manage that investment.

If you're looking to get started in real estate, look at a crowd funding solution like RealtyMogul. It works similar to LendingClub - you commit as little as $5,000 towards a property. When the property is fully funded, you become an owner, and will receive your share of the earnings and appreciation in the property.  Check out RealtyMogul to learn more.