That's a reasonable amount as a starting goal. Do you have any skills you can sell or freelance? With the most basic of skills you can't expect much more than being an assistant, but if you have something greater than that your goal will be easier to achieve. Once you have a bit of starting money it becomes much easier to earn more, given you know what you're doing.
Here's an amazing thread with basic methods to make money: https://www.blackhatworld.com/seo/a-couple-beginner-tips-low-cost-free-money-making-methods-for-beginners.999534/
Most of the things there are free, but a bit of starting money makes it easier. Don't rush into it though.
Generally, the quickest way to get money online is to advertise and sell a product or a service. It doesn't have to be yours, you can be an affiliate or a reseller too.
Once you start reading a lot here on BHW you may get overwhelmed with information. Most of us have been there at first, so pick the way that you think is easier and stick exclusively to that one at first.
Remember, making money online is not easy, but also if you can make $5 from something online, you can probably also scale it into $500 with enough work.
