Tasks are at the heart of Structured. They can contain various information and can be used in different ways. Compared to normal to-do lists, tasks in Structured usually have a time and duration associated with them. In that aspect, they are very similar to calendar events. Since the tasks are pretty simple, they don't need much more explanation, but if you are interested in some of the more advanced features, take a look at the How-To Articles below.
Yes, if you select Weekly you'll be able to select on which weekdays the task should repeat. Check out
Those tasks are just normal tasks, which were created for you at the beginning. Therefore you can edit or even delete them, like every other task.
Pro Tip: Change their recurring interval to only weekdays and create new (later) ones for the weekend. To learn how, check out