Really, really, REALLY, REALLY look at what you’re trying to draw. Then draw a lot, no matter how cruddy you think it looks. Just about anybody can draw if they really try, it’s whether you have the patience to keep at it.
Most of the drawing problems I noticed in others was they did not have the patience to truly look at something and then truly try and emulate it. They would half-ass it and miss all the important things such as the flower vase was only half as tall as the cello in their still life, etc.
I only truly took an interest in drawing during my midle-school art classes and a stint in detention. I drew as a hobby through high school, going through the ups and downs of trying to stick to a style when I shouldn’t have. I went to college for a fine arts degree and it did help, but more because they forced me to do still lifes when I otherwise would not normally have.
Anyway, back to the learning how to draw thing. Sit your butt down and make a still life. Then try to draw that still life in pencil or charcoal. Notice how tall things are in relation to one another, then correct when you make mistakes. Get up and walk around the still life to understand how and why objects look the way they do (the tops of cups viewed on the side, no matter how close to level you are, always make an oval, not a cat’s eye for instance).
My teachers loved to make you work in vine/stick charcoal because you couldn’t erase well and you couldn’t focus on fine details at first. Always start “big”, that is, focus on the overall relation of objects to one another and mark them out on your paper as guidelines, and then get to the detail later. Ideally, your paper should be a big piece of newsprint if you’re using charcoal. No namby-pamby 8.5" x 11" (you can use that if you only want to use pencil though). Then you start filling in the details. You’ll probably notice by this point - objects don’t usually have hard outlines the way cartoons draw them. Really, their shapes are defined by their shadows! So you can do outlines to guide you, but don’t do them too heavy, and focus a lot on the shadows. This is why it’s good to start in black and white - so you can focus on learning how to draw forms first. Charcoal is also good for this because it’s good for laying down thick shadows.
After you feel pretty confident you can start playing around with color pastels, or move on to drawing people, or try out oil paint, or do pretty much anything you want. I find color to be very hard - even now I am still playing with warms and colds and what a pale person’s skin REALLY looks like on a warm day - how their shadows are actually blue but their cheeks pink - all that fancy stuff.
After you feel like you can do a pretty good realistic scene you can move on to drawing whatever you want - stuff from your head, the boats in the quay, space scenes, whatever. The whole idea is you learn to draw from life, and after that you learn how to stylize that based on your perceptions. That was the whole idea of the impressionist movement - they drew what they felt from the scene more than what was truly there. But you can only extrapolate different styles and perceptions from reality. You can’t start with “How to draw Manga” and really learn how to draw from that. You have to start with what’s right in front of you.
Draw yourself naked in a mirror. Draw the 50 million poses your hand can take. Draw your cat. Draw a stuffed animal. Draw the people sitting on the train. Draw, draw, draw. Practice is what does it. There are pointers to learn - drawing is the art of relation. The human face has a lot of relations to make this obvious. The sides of your nose line up vertically with your inner eye. Your mouth corners line up vertically with the middle of your eye. Where the tops of your ears connect to your head are straight back from your eye corners, the bottom of your ears line up with the bottom of your nose. Etc, etc. Being able to see these sorts of relations and use them to match what you’re drawing, even on organic objects, is the key to drawing well.
BTW, I always thought I couldn’t paint even though I could draw. That was because I had only ever tried acrylic and it dried too fast for me. Then I was able to try out oil paints and it was an absolute dream. Expensive, but definitely worth it.