- it is not necessary to rewrite each UserControl in a separate project (.dll) and then drag it into the main window?
Projects are best done by subsystems or major components in the project, taking into account the existing dependencies. Without seeing your situation it is difficult to recommend a particular solution, but in any case, hardly each control is push in a separate project.
- in General, you can read about the correct application architecture (as I understand it, the question for this topic)?Raffaele Garofalo, "Building Enterprise Applicatio...
- I would like to start working with your project. Visual Studio Team Services such as appropriate, from where to start learning this service?
It is better to start with Git. It is certainly possible to work with Studio version control, but since you did not work more generally with anything, git would be more versatile skill due to its overwhelming popularity. And Yes, most importantly - you do not need to immediately use some service, the project can be versioned and on the machine and pour in VSTS if necessary. It's amazing how you still did not use any VCS, apparently you are careful and patient man)
Yes, make sure that you understand the MVVM. It may be worth it to pick up the framework or to collect the basic library, if there have been developments.