One of the first questions people ask when joining my life drawing classes is: 'how long before I can draw the figure well?'
With absolute beginners, usually with 25 hours of tuition, most people can be proficient with drawing the figure. You can learn the principle of the 'thumb and pencil' method in couple of sessions. Then it's mostly practice. Once you are able to draw with confidence, the next stage is to add tone to an otherwise flat drawing. You are best to keep it simple, that's why I recommend using charcoal, as it takes away the complexity of colour. Plus it allows you to achieve very subtle shifts in tone, which you will encounter when observing flesh tones.