My first investment requiring money down was half from my own savings, and half from a deposit I received by buying a property in Tokyo. Long story short, 100% financing at low rates is available through a few banks in Japan. One property I bought with a 0 down loan has a pizza shop on the first floor, and in Japan stores generally have to pay 10-12 months rent up from as deposit. So when I obtained the property I received the deposit after closing in cash - about $60k in total.
The shop had just resigned a 3 year lease extension, an so I decided to use this deposit along with my own saved up cash as a down payment on a property in the US.
I've always been good about living within my means no matter what stage of life - live within what you can afford and you'll always be able to save some money, leading to a lot less problems in the long run. That being said what I did sort of goes against that idea. Was it the safest or smartest move? Maybe not. But it's worked out so far and since then I've been able to build back up that deposit amount plus a bit of a buffer.
Long story short - keep your eyes open and keep asking and taling to different people as you never know what opportunities you may come across. This was never my plan by any means, but when I saw the opportunity I jumped at it.