Nice start on drawing figures. You need to work on your hands and feet. Line-of-Action has a section on hands and feet. You also need to do a study of human anatomy - both muscles and bone structure. The internet has a lot of free information on these subjects. Why study these items. No matter if the figure is clothed or nude, you need knowledge of these areas to do a good job. I would recommend you start out with a stick figure (an armature) to get the action of the figure worked out. Once you have things worked out, you can expand the flesh of the figure. One thing, to become proficient in drawing figures, is going to take longer than 2 weeks. It will take a lot of work on your part. Practice makes better.
You might check out this book: "Morpho: Anatomy for Artists" by Michel Lauricella
Vcuubed, that's a very good job you've got on these sketches you've got there. So, if I was to give you some improvement here and there, it would be to focus on the silhouete and the lines of action and rhythm, in some 90 second poses, pretty please? The reasons why are because, a) you'll get a much better idea on the overall gestures and poses. and b) you would be able to push the poses far beyond their usual limits in their forces and forms.
Hope it's been completely, definitely, and absolutely usable.
P.S. Go for 10 10-second hands and feet. They help, too.
Your drawings look really nice. There are some moments in which your line feel really confident but there are some moments in which you seem to have a lot of doubts and that is kinda clear in the line quality. I really like the 5 min drawing.
I think that in the short ones you focus a bit too much in the countor. With those short poses it is better to try to take the energy of the poses. It is useful to try to exagerate a bit so you get a better grasp of what your are looking at.
There are a couple of resources that i am learning from right now: One is Proko and the other one is Lovelifedrawing both of them are Youtube channels. If your are interest go check it out they migh help you.
I think the main problem that I can see is really visible on the 5 minute drawing. You're focusing too much on the contour lines and that is getting in your way of describing the form propperly. I'd recomend you to search and apply the Reilly's method so you can practice seeing the flow of the body instead of the contourlines. Proko channel have great videos about this subject, lectured by Tim Gula.
The other thing, learn anatomy too, so you know when something is off. For beginners I'd suggest Loomis's or Michael Hampton's books. I personally think that Hampton's will suit you the best because of the boxie aspect will help you to see the volume.