Hi
Are you running on a Mac or PC? What OS (Windows 10 / MacOS Catalina / etc)?
Have you installed the Origin application? You cannot download games from the web page, you must install Origin on your computer. You can download and install from here: https://www.origin.com/store/download
If you are on a Mac running Catalina, SimCity will not run. Apple dropped support for 32-bit games like SimCity, beginning with MacOS Catalina 10.15. There is more information in this post: https://answers.ea.com/t5/SimCity-2013/Mac-SimCity-and-MacOS-Catalina/m-p/8298578#M127940 , including some options for running 32-bit games after upgrading to Catalina.
If you are on a PC, please reply back and let me know if there are any error messages and if SimCity ever starts.