There are several tools that you can use to track the traffic to your site, and data about your visitors too. You may not be aware, but if you already have a live website designed, your hosting company may have some basic tracking tools within your cPanel. One of these is called AWStats. Admittedly, it may be very basic data, but it does provide you with some very useful information.
Beyond that, some of the most popular traffic tracking tools are often paid services if you want more detailed information, although some also have a free version that provides the basics. In some cases, the services are free if your traffic levels are below a certain number. Examples of these services include W3Counter and SiteMeter.
The most popular traffic and visitor analytics platform on the internet is Google Analytics. It is a free service and allows you to analyse multiple websites from a single account. The depth and detail of the data Google Analytics provides is excellent and another benefit is it can be linked with Google Ads if you are running PPC marketing campaigns.