It depends what you're interested in drawing.

If you're interested in cityscapes, landscapes, buildings, architecture, the thing you should start learning immediately is perspective. There's a lot of good youtube videos about it. Let me tell you something - I have a pretty wholesome art degree, but at no point in art school could anyone explain perspective to me beyond 1 or 2 point. It's that tricky, and once you get it - it sticks. The people on youtube got it down. (Also, you're more likely to learn about perspective and lighting at a 3D art school, ironically.)

If you're interested in drawing people, portraits, animals... Then you really need to learn the anatomy of your subject. It's also kind of tedious and tricky, but it makes drawing a lot less confusing and more of an innate process. Find some anatomy books, draw real people and animals, take a class in anatomy for drawing if you can.

I took a course recently with a matte painter, and he spent the whole course emphasizing how correct lighting makes artwork almost instantly good and more believable. Lighting is one of my weak points, and I really saw what he meant by that when he helped me fix my mistakes.

Anyway, those are general long-term pointers. If you're just starting out, the most important things are: to not be hard on yourself (you're supposed to have fun right?); don't let anyone tell you their way of doing something is the right way, because there is no such thing; don't obssess over getting THE BEST pencils/paints/whatever other material - it doesn't matter in the beginning; and practice a lot and as many different ways possible. I'd say draw is a lot more mental than mechanical actually, and it's almost like learning a new language.

I also feel like saying "Just accept your first drawings are going to suck", but it's not true necessarily. Some of the first drawings I ever did were the most imaginative and most thought out, even though they looked horrible on a technical level. Just don't worry about them being 'good'.