Draw a Box [0] comes highly recommended. All lessons are free and are taught from scratch. Everything from absolute basics is thoroughly explained and demonstrated. Paid courses by Proko [1] are also said to be of very high quality. I have never bought one, though. I would also suggest that you look into digital art. Sketching/painting/drawing paraphernalia is expensive with time-consuming upkeep and hard to carry if…
I think it builds sort of slowly, and you need commitment to get through to the part where you're drawing "the rest of the owl" so to speak, aka the fun parts that aren't just endless pages of boxes in perspective.
But, there really isn't a shortcut anyway, and it's worth it, and this course is presented really well, for no money.