Two thoughts come to mind. First, at 27 you have a whole life in front of you, so whatever you do will be right if it is directed correctly. Second, pick a goal and work towards it (e.g., pay off medical debt; or pay off condo mortgage). Always remember, as you succeed in any one of these, then you can broaden out into other investments opportunities (e.g., stocks, mutual funds, real estates, etc.). The choice and timing are yours to call. My basic point; however, is while you are young “focus” on a GOAL and go after the goal aggressively.
Last but not least, you can also earn money online by building an online community, although the monetization strategies you can pursue will vary a lot depending on your goals. You can build a community with a blog, for example. You can also build an online forum and charge people for membership. You could even build up a Facebook group and use your influence there to sell and promote products.
If you're unfamiliar with the concept of arbitrage, here's how it works. Wikipedia describes an arbitrage as effectively, "the practice of taking advantage of a price difference between two or more markets: striking a combination of matching deals that capitalize upon the imbalance, the profit being the difference between the market prices." Clothier was able to identify arbitrage opportunities in the grocery industry with precision.
Tenants sounds good, but can be a toxic problem as I recall before of one studying Religion and Ministry somewhere and claimed to be clean and laid back, but came to light by another tenant he stayed with to have a bad temper, bad attitude and never clean up his own dishes and have his stuff scattered in living room without first discussing with his roommate and always asked other roomie for rides and money as a moocher and would get pushy if his roomie refused as unable to at times.
Build your audience on a course community: If you’re just getting started building an audience for yourself and want to leverage communities already actively looking for content you can choose to host and sell your online course on a site like Skillshare or Udemy. These are easy, cost-effective ways to build an audience and test your niche to see if there’s demand for it.
Turn your photographs into cash via sites like Fine Art America, which lets you upload your images to sell as prints, t-shirts, phone cases and more. Other marketplaces for photographers include SmugMug, 500px and PhotoShelter. Some sites require a subscription but may provide features ranging from cloud storage to password-protected galleries and a customized website.