A few ways of earning a legit income online are.
Freelance
Freelancing is a great way of earning online income if you're good at creating logos or writing content or doing other online services for people.
Start A Blog
Start a blog or other website and create fantastic useful content that people will be glad to share with others and will help them out for what they're searching for.
Once you get your website going and have content on it then you can apply for Adsense.
It's very hard though to get accepted into the Adsense Program and once you get into it. Do your very best and everything in your power to prevent an Adsense Ban. Because once you're banned from Adsense then that is it.
You can also use Affiliate Ads on your website which can earn you up to $100.00 per sale.
Or create your own product or service such as an E book that you can sell that will solve someones problem.