I run a real estate team that sells houses. I have eight people on my team and many of them are real estate agents. I also have assistants and contract managers who help with paper work and the ins and outs of the business. I sell houses myself (mostly REO and HUD), but many houses are sold without me doing any work. I get a part of those commission checks, because I set up the team, offer training and help my agents succeed. My business is not truly passive, but if I want to go on vacation for a couple of weeks I still have money coming in without me doing any work. There are thousands of business that can be started, but I think becoming a real estate agent is a great way to become an entrepreneur.
1) If your property is not under rent control, you have the ability to raise rent to market prices with proper warning. In SF, I have to give tenants a one month warning for up to a 10% increase and a two month warning for up to 60%. Rent control limits to an inflation index, usually around 2% a year, which is why initial pricing and tenant turnover is important for better profitability.
Creating passive income is one of the most important steps towards retirement. Passive income is money that comes in without any work from you. Stock dividends, rental property income, interest on notes are all forms of passive income. Truly passive income is almost impossible to achieve, because every investment involves some sort of work. Stocks are fairly easy to buy, but still require research, while real estate is more difficult to buy, but can produce much higher returns.