To create a new package\model on AX first you should understand the concept of Packages and Models on AX7, click here to see the MS wiki tutorial or use this video.
On VS go to the menu Dynamics AX 7\Model Management\Create model

Setup  your model parameters:

Obs: If you want to create a model inside an existing package I advice you to identify that on the Model Name and on the Model display name. This will help you when you are selecting and using your model on your project. Example: If you want to create a new model on Application Suite, I would name it as “NewModel (Suite)” and use the same on the “model display name”.
Select if you want to create a new Package for the new model or if you want to create the model under an existing package.

If you choose “Create new package” remember that with this option you will be able to just extend element from referenced packages. If you need to customize I advice you to create 2 Packages:
• A new package for your elements and extensions.
• A new model inside “Application Suite” for example to do customization (SalesTable form). Don’t forget to make your new package as referenced package to this model, so you will be able to access your element on the customization model, ex: new tables.
Select the referenced models for your new model.

Usually you will need to select the models Platform, Foundation and Suite. Don’t worry if you forget some model because you can update your model using the Dynamics AX 7\Model management\Update model parameters…
If you want to use this model as a Unit Test and Automated Test model, select the references to Test Essentials and the Form Adaptor model related to the model that you want to test.
Finish your model creation and select the extra options to “Create new project” and “Make this my default model for new projects” if you prefer.

To see all models dependencies, go to “Dynamics AX7\Model management\View package dependencies”.