I see. Yeah, if you plan to work with steel, iron, aluminum, you'll certainly want to take a class on welding and learn which sorts to use for which materials. As far as tables, it depends on the look you want. If you're thinking wrought iron, you're going to have to learn some blacksmithing. If you're thinking tube metal or sheet, you're going to need to cut, bend/brake-form pieces and then either weld, rivet or bolt the pieces together. Each of these methods present their own set of challenges and considerations.
Stuff like candlesticks...well material and shape is a big consideration. If you're thinking ornate stuff with a frilly carved appearance, you'll either be looking at welding chunks or iron together or learning to cast metal in forms.
If you're looking at slim symmetrical curving candlestick shapes, you can turn brass or aluminum on a lathe for an elegant look.
Basically, methods and tools requires are determined by the material being worked and the desired outcome. You cannot work with brass and steel for example in the same way. And even within a metal type there are often different alloys designed with certain purposes or manufacturing processes in mind. So, if you have a community or vocational college nearby, I'd strongly suggest you see what sorts of classes they offer in your area of interest. It's the best way to learn what you need.