Scavenge materials wherever you go. Don't be shy about asking for things when you see them on a street corner or in a field. Your art materials may be someone else's trash, and they are often happy to get rid of it.
Familiarize yourself with your materials by working with them informally. Juxtapose different pieces of iron and glass in ways that don't commit you to their form, and continue moving them around and rearranging them until you find a composition that pleases you.
Contrast the iron with the glass in dramatic ways. These two materials have very contrasting natures, the first being heavy and strong and the second transparent and delicate. Use these characteristics as a theme of the work that you make with them.
Learn about different methods of working iron. Take a welding class and learn how to cut, bend and connect pieces of iron.
Learn about the many ways of working with glass. Glass can be melted, blown and shaped, or worked into a sculpture in a found form. Shards of clear scrap glass contrasted with sinuous, melted colored glass can create dramatic contrasts within a sculpture built out of scrap iron.