You can set up a website, gradually build up the content (articles, videos, podcasts, etc.), then eventually monetize the site through advertising, affiliate marketing, or even the direct sale of specific products or services. Even better, you can generally find whatever services and technical assistance you need online and free of charge. Later on, when your site develops a reliable cash flow, you can begin working with paid providers who can take your blog to the next level.
If you have nothing of value to sell from home then retail arbitrage might be a better option for you. Many people partake in arbitrage to earn a little extra money, and for some, it has even become their full-time job. Retail arbitrage is the buying of goods at a low price and then selling them on a different platform at a higher price. Sales in shops provide ideal opportunities to pick up products for next to nothing. These can then be sold on eBay or Amazon for higher amounts, making you a nice profit.
One of the cool things about Google AdSense is that it's so easy to get set up. If you have a blog or website, you can sign up for a free Google AdSense Account. From there, Google will give you a unique code that you will paste onto your website. Google takes it from there, tracking your page views, traffic, and earnings on your behalf. There is no upkeep or maintenance to get this thing going, which makes it a no-brainer if you have a website already.