I am 27yo,have 5000$ to invest,good credit history but no income. How can i start in the real estate business?

babyc has no clue.

You do not buy property at tax sales, you buy the TAX DEBT. You do not own the property.

You do not have enough to start as a real estate agent, and you can't do anyting in real estate business, other then buy and sell for yourself, without a license.

5k will not even cover closing costs if you tried to buy something, but without a job that is not very likely.

Your best bet is to go to your local county tax sales. For a small amount of money you can purchase properties being sold for back taxes. There will be a public listing in the area newspaper of properties. Go to your county courthouse to get the tax sheets on the listed properties, then do your homework. Some properties can be bought for as little as $100. Each state has requirements on how long you have to wait before you can take full possession of the property and then sell it yourself. Many are in poor condition, but can still have a good profit margin when sold. Start small, research the properties and what has sold recently in the same areas to make the best picks.

You could buy some property in the desert. But if you do not go to work you would be losing that property to the tax man.
How would you get a loan with no job? At 27 years old and no income did you save up that 5k. with your allowance?