As an author, you need a website. Your site could be something simple like a landing page to provide links to your books online and to collect email addresses for your contact list. But you could also have a more complicated website with multiple pages and blogs to keep your target audience coming back. Your site is also a great place to sell your books if you have some on hand to sell.
Technically, your site could be hosted on a free blogging platform like WordPress, Tumblr, or other free services, but you can also pay for hosting and build out a full website. The free options are typically easier if you do not have the technical skill or cannot afford to hire a website developer, the free options are a better and faster way to get your author website online. Overall, having a hosting account and a full website is generally better, though it can take more time to maintain. Research all your options before making your decision. I have some affiliate links for hosting accounts that I recommend on the affiliates page and you can contact me if you would like to talk about building a website.