There are many online businesses you can start. Some of them cost money while others are free. If you are new to online businesses then you mine as well start a business for free. That way you have room to make mistakes without risking any monetary loss on your end.
Now the big question is, "What business can I start online for free?" The most profitable free business would be affiliate sales. This is where you sell products that other people are selling through an affiliate program. The number one affiliate website on the internet is ClickBank. This website has been around for many years and was one of the first affiliate programs to ever exist on the internet. They let people from all walks of life sign up for free accounts. Once you sign up for an account, you can immediately navigate the ClickBank marketplace filled with products that other members are selling. Of course, you won't be buying these products. What you will be doing is becoming an affiliate of these products. You won't even have to sign up or seek approval from the seller to become an affiliate either. All you have to do is click the "Promote" button of the listing and then click "Create" on the pop up window. At this point, you will be given an affiliate link that you can advertise anywhere. Then when somebody goes to that link and completes a purchase on the sales page, you will be given a commission for that sale.
The hardest part about this business is getting people to go to your affiliate link and purchase the product on the sales page. That is why you first have to choose a product that already has a lot of popularity. When you are navigating the marketplace you can filter the listings by popularity in order to see which ones are selling the most. These are the ones you will want to try and sell because they already have plenty of consumer demand.
If you are looking for places to advertise your affiliate link, try using social media as a free method of advertising. If you have a lot of friends on your Facebook or Twitter profiles, then just send them a status update with your affiliate link in there. You could also try purchasing a domain name related to the product on the affiliate page and then mask the affiliate link with the domain name. There are so many free or super inexpensive ways to make lots of money as an affiliate on ClickBank.