If you're looking to grow quickly and aggressively the key is going to be how you leverage the $50,000. There are a few options. You can put it into a value add property, stabilize it then refinance hopefully getting back all of your down payment back. People refer to this as the BRRR method.
A second option you'd have is leveraging some of your money with other people's money. I am a part owner in several rental properties and haven't put a penny of my own money into them. What I do is find a good deal, typically a big value add. Then use other people's money for the down payment. You give up equity of course, but now your nest egg is still at $50,000. It's a matter of how many investors and how many good deals you can find, rather than how far you can stretch the $50,000. As you build a track record, more and more people will want to invest. At my current point there are way more people trying to invest than I have deals for. It isn't what I do full time so I just don't have the ability to keep up.
I'd recommend starting out with the BRRR method for now though. Find a place that needs some simple renovating offered at a discount. I'd use hard money to get in there quick, get the work done, then get the tenant in.