Nice job on your first-ever attempt at Force, trex_junior, very beautiful job.
Now, if I would, if I could help you out one something with your study, it would be these three--even if I'm not really an expert on figure studies (I'm sure)but I'll try and do it.
1) Yes, this drawing looks like you've been applying the Force properly, in terms of the gestures.
2) I see your line weights look just as fine to me, but why don't you please vary the line weights, in 15 minutes of 30 second figures, from the Force book?
3) Love where your are going for - or tried to go for- in your figural shading. However, nice try, but the figure doesn't look and feel like it's shaded strongly yet. Could you please go check this out here.
The reason is because: a) you'll improve fairly quickly and effectively in your quick sketches in your loose frameworks. b) you'll be a lot more strongest in your line thicknesses, if you go for a softer pencil, like a 4b pencil. c) You'll really get closer to what you want and need to aim for in your sketching.
Hope they've been completely and totally useful in advance.