Different people, different plans. If I want to start a brand new online business I make sure I have the time for it(right now I don't, too busy with on-going projects + my personal life).
Obviously, you need to find a market, a need, the clients, get sales, $10k is not that much, you could try to do the Aliexpress to Amazon bundle thing, many does this in 2017, simply buy from Aliexpress more stuff, make them a good bundle and sell on Amazon, for fast sales you buy advertising directly from Amazon, others use Facebook and so on, so this business is to buy low sell high and keep the profit.
The second is YouTube the professional way, you team up with couple good friends, and aim for viral videos, buy high-end video equipment, get some original ideas, shoot and edit the videos professionally, optimize and publish the videos, handle the marketing, you can get in touch with other companies looking for viral videos and you give them the right to publish your video in exchange for promoting you channel etc...