Best Investment to Make right out of college

So I am definitely one of the very, very lucky people who will be graduating college with no debt. Currently I have a summer internship that I have accepted at a top private credit shop (Antares), and obviously my main priority is getting a return offer after this summer. However, for the sake of thinking optimistically, let's say I do get the return offer and accept it. I don't have college debt, won't be working in SF or NY so COL isn't going to break my balls either, don't see myself buying bottle service for 10 every night either, so I will have some money to invest (ideally lol) after not too long into my career.

If you were in this position, what would you do with the money you'd be making? Open to all suggestions. I have invested in the stock market before, and plan to continue to do so, but want to explore other ways of generating income. I know the benefits of owning rental properties, I want to know how possible this is to start within a few years out of school, or any other good advice for this kind of investing. Obviously, there is huge benefits to investing in or owning a small business, but I don't know how to go about that so advice there would be great too.