Startup manual:

Before running tasks rebuild solution.
You need to run allTasks in Tasks Runner Explorer (View > Other Windows > Task Runner Explorer) after first checkout from source save.
If sass does not restore, run npm rebuild node-sass in src\BaseApp.Web folder.
To override appsettings.json for dev environment use Manage User Secrets
You need to create and apply all migrations (see EF docs belows for details)

EF docs:

For migrations use EF Core Package Manager Console:
Open console (View > Other Windows > Package Manager Console) and select default project src\BaseApp.Data.ProjectMigration. Then run ef commands (Update-Database for example)
For more details visit: powershell docs

WebApi docs:

Convention: All non-get methods with one parameter binds FromBody (or FromForm if IFormFile presents). See ApiControllerConvention for details
To view help pages use /swagger url)