@Ranya Hassan - MS Cloud - IO HWAN This document which I shared previously covers how you can have Mutiple projects in the same workspace. There are two ways that are documented, and I have tested the same at my end and I can see multiple projects are added to my workspace as below.
I have tried option two at my end and you can see in one workspace I was able add two different functions projects.
If you need to create the different workspace for different azure function local project, then you can simply open them from explore and save the workspace individually
To deploy the function that has multiple projects on the same workspace then you can simply click on function on the workspace panel and then click on Deploy to Function App and now it will ask you to select which function you want to deploy from your local machine and then you can configure the resource and other details.
In case if I misunderstood your ask then please let me know.