最有可能是因为您没有安装任何SDK.

Most likely this is because you don't have any SDK's installed.

在Android Studio中，转到工具-> Android-> SDK管理器，并下载新项目所需的API，然后尝试重新启动一个新项目.之后，您将可以选择要编译的SDK.

In Android Studio, go to tools -> Android -> SDK manager and download the API's you need for your new project, then try to start a new project again. You will be able to pick an SDK to compile against after this.