You can manage all your NuGet packages from the NuGet Package Manager, which you can invoke from the Visual Studio Tools menu - NuGet Package Manager | Manage NuGet Packages for Solution....
All the installed packages will get listed under the Installed tab, whereas the packages with new updates on the server will get listed under the Updates tab.
The installed packages may have overlay icons to denote the status of the package. For example, the blue arrowhead (as shown in the following screenshot for our package library) denotes that an update is available, and the green checkmark (as shown in the following screenshot for the Newtonsoft.Json library) denotes that the library is installed:
You can configure NuGet Package Manager to allow NuGet to automatically download the missing packages of a project/solution. You can also ask it to automatically...