To get Intellisense on your umbraco models from modelsbuilder we have two recommended ways of achiving this.
Install the full ModelsBuilder (https://github.com/zpqrtbnk/Zbu.ModelsBuilder) nuget package and change the ModelsMode to Dll and then build your models in the Umbraco backoffice. This will generate a Dll that will give you intellisense.
Create a new project in Visual Studio that will contain your models and make it build into your web project. Change your ModelsMode to AppData and add these two settings to your web.config: