How to Design an Desktop App for Beginners?

I want to design a desktop app, but most of the guides I find are for mobile or some other type of app, and I don’t see any templates. (And if I do find something useful in the handful of templates on the site, the only way to import seems to be to import the entire project in another window and copy paste into mine?)

How do I handle a Windows title bar - do I have to design that 100% from scratch? Are there any widgets like has? I’ve read through the beginners guide and watched a few tutorials but I’m still confused on these.