I myself have recently come to these forums for advice on how to refine my gesture drawings, but seeing as you're starting out and I've been working at gesture drawing for a few years, I hope my advice can be helpful!
Gesture drawing is about finding and capturing the movement of a figure. This doesn't necessarily mean a model in action, even when someone's just sitting in a chair there is movement in their pose, i.e. the curve of their spine, the angle of their shoulders, the tilt of their head. But when you're just starting out what I suggest to avoid is getting too bogged down in the details of human anatomy--gesture drawing isn't quite figure drawing, the goal isn't to reproduce a picture perfect carbon copy image of the model. Do a quick Google image search of "gesture drawing" a note how simplistic they can be, some styles are merely just lines.
Line of Action itself has a great & quick tutorial here on how to capture the human form in movement with just lines and simple shapes, which is really all you need for gesture. Use this site and others like it (QuickPoses, SketchDaily) to practice your gestures. They are meant to be quick drawings to keep yourself from bothering with the tiny details as gesture drawing is about the big picture of what the figure is doing, 2-3 minutes is good to start. Give yourself a few seconds to study the pose, note the form and flow of it, and then spend the rest of your time drawing it in those lines and shapes. If you're using pencil, I personally find it helps to have an oversized drawing pad, the kind you need 2 hands to carry, as working big and giving yourself room to draw from the shoulder makes it easier to capture the curves of the human body. If you have to work small, use a pen, the ink helps you make bold and strong lines.
There is also a book I am currently reading called "Gesture Drawing for Animation" by Disney animator Walt Stanchfield. It's available online for free in PDF form and it doesn't just pertain to animation, Walt gives great advice and insight on the nature of gesture drawing and how to train your eye and your mind to quickly see the figure all in one go.
The anatomy of individual body parts might trip you up in the beginning, that is a problem that's plaguing me even now. When you're gesture drawing, your mind is essentially supposed to think "form", you don't want your mind thinking "head...arm...other arm...torso" because that can make your work stiff if you're focused so hard on acurately rendering the details. If you find that happening maybe save the more serious anatomy study for later, think of gesture as Level 1 and anatomy as Level 2--you have the cheat code to skip levels, but Level 2 will probably be easier if you go through Level 1 first.
My last bit of advice is to try and do gesture drawings every day. A whole page in a sketchbook, or a 15-20 minute session each day. Because gestures are done so quick, you need a lot of them to grind out that XP and level up, and working everyday is the fastest way to do that.
Sorry if I rambled a bit and sorry this answer is so long, but good luck!