How to build model in dynamics 365?

to build a model in dynamics 365

 just go to dynamics 365 Tab in Visual studio

select the model that you need to build 

also, you can build the referenced package if you need 

you can see multiple options in the options tab 

like build reports if you need, synchronize database during the build,,,, etc

you can see more details about this options here 

https://docs.microsoft.com/en-us/dynamics365/unified-operations/dev-itpro/dev-tools/build-operations

you can build your solution as the below 

The solution can  have multiple projects when you build the solution, all projects built 

or build specific project only 

results for the build:

Thanks.