Explanation: I think
Hi! I, too, am trying to learn a form calligraphy which is brush lettering. During grade school, we were given lessons and practical work on the usage of speedballs. What I learn through this is that downward strokes need more pressure and produce thick lines. Upwards strokes are require less pressure and thus create thin lines.
The difference between cursive handwriting and calligraphy is that calligraphy allows you to take the pen off the paper. This means more control in forming the individual letters. It is quite hard to master at first which is why you need to practice the strokes first before you move on to the alphabet.
To do this, I would suggest you watch videos on the basics of your chosen form calligraphy. Download free beginner worksheets on basic brush/pen strokes. Basic brush strokes are what make each letter. I would suggest printing the work sheets and photocopying several copies or use tracing paper on top to practice.
Do not buy expensive pens, brushes, and inks yet. Make do with the cheaper ones because there is a bigger possibility of you breaking a pen or brush tip while doing the basics. Softer or thinner pens are a bit harder to manipulate and require intermediate skills, chose one that is thicker or firmer.