is there any way to create a GUI in Monodevelop using the c++ language? i know about the built in Stetic development tool , but it seems to only work with c#, and i need it for a c++ project (for my class).
C++ has many different toolkits for handling GUIs, you need to specify what you want to achieve.
You can use monodevelop and Stetic tool to build a GTK interface for example, then implement your logic in C++ (which GTK has, of course, support for). I personally never attempted something like that, so you might wanna check the tooling and support, but it should be theoretically possible.
Worth noting is, XAML is basically cross platform in the context of Universal Windows Applications, so you might wanna check that out first. Look for Xamarin and try to stick to current information, the platform is a big technological shift for Microsoft.
This is outdated, but gives you an idea
Using C++/Qt and QML with QT Designer (as suggested by @Joachim Pileborg) is one of the best paths to undertake for a stable, cross platform, native looking GUI toolkit.