Yes, 2...If I create the task manually in task scheduler, Veeam will do "Incremental Backup"?
As per Veeam guide, "C:\Program Files\Veeam\Endpoint Backup\Veeam.EndPoint.Manager.exe" /backup...this command is for "Incremental Backup".
Just use the Task Scheduler CreateTask ... wizard.
When you get to Action - Start a Program - C:\Program Files\Veeam\Endpoint Backup\Veeam.EndPoint.Manager.exe /backup (you might have to use the ")
Take a look at some Windows Tasks to get a better idea.
The wizard is fairly self-explanatory, but you will have to figure out a backup schedule.
I don't know anything about Veeam. I would think the soft would be capable of creating its own backup tasks and schedule - but since you are asking about how to do this - then evidently it must not.