If you have hands, you can sew!
I second that! Being able to sew is like being able to draw or cook. Everyone
can do it, even if your first efforts are pretty awful. But like drawing or cooking, good sewing is a combination of learning "skills" (techniques and tricks that others use to produce the kind of work you want to emulate) and observing carefully so you can reproduce whatever it is you want to create. If you start out trying to draw horses without having a horse to look at, or baking a cake without knowing what the basic ingredients are, the results will almost certainly be disappointing. But if you start out drawing that coffee cup in front of you, or baking a pound cake from a recipe, you will find you can do it after all.
And in a way, this kind of "upcycled" clothing is like baking a cake from a mix: you can start with existing items and alter them without having to worry about what order to put the pieces together or facing that terrifying moment when you first cut into that piece of expensive fabric. If you screw something up so that the end result is unwearable, you can add or subtract bits until it works again, and it'll look like a creative flourish.
Yes, you will need a sewing machine, but you don't have to go out and buy the latest electronic marvel. A $40 one from a thrift store is much better for novices: less choices to make and less to go wrong. You will also need an iron if you don't already have one (and not everyone does - I pretty much only
use mine for sewing!) and it's worth buying a new one because too many used ones are burned out. But a cheap one will do to start out with.
The rest is just pins and thread and measuring tapes and little stuff you can pick up as you need them. Practice using the machine on fabric scraps of all kinds until your stitching is professional-looking. Try to copy the different types of seams on your own clothes to learn how they were done. It's much better to learn to sew on scraps that you will throw out than on a garment that you're planning to wear. And don't try to make something like a jacket or an a-line skirt as your first attempt. Start with an apron or a vest instead. Avoid anything that requires zippers or lining. When in doubt, sew on lots of buttons.