My high school offered drafting as a course. In drafting we used a program called AutoCAD to design structures such as shapes and building. It was a great class that gave a good baseline in architectural design with a design software. This was a high school course so it wasn't the most advanced class in the world but was a great start. If your school offers this course take it, and if they don't try to find somewhere that may have a design program such as AutoCAD or find a free program so you can get a start on it yourself. Hope this helps!
The architecture standard these days in Revit, so I would recommend you download that software first and try to build the house or apartment you live in for practice. I hope this helps!