To know your website performance, you would need to use two tools, Google Analytics and Google Search Console. They are free but very powerful.
Google Analytics
allows you to check data of your traffics, such as the ratio between organic search (SEO) and paid search, bounce rate between the two channels, etc. However, it could not show you what keywords converted from organic search (SEO) due to policy changed a few years ago. Therefore, we would use Google Search Console in parallel for the SEO performance analysing.
Google Search Console
allows you to focus on organic search (SEO) traffic. It helps you to identify your keywords ranking on Google as well as their click rate. Google search console is not limited to keywords report only, it also helps you to check the technical configuration of your website. If your website get errors or penalized, reports will be given by Google Search Console.