Its the tri-force of the camera world. When i first bought a DSLR, a Nikon D3400, i knew NOTHING about cameras. i didn't know what any of the buttons did or meant. it was intimidating beyond measure and i didn't think i would ever reach a point where i would consider myself "knowledgeable" about this stuff. I mostly used the automatic setting, but as i started to pay attention to what the automatic setting was doing to the camera in different settings, i began to understand. So, there is no tutorial that will have you using a camera the way you want, i only hope that i can provide some tidbit that might create some understanding when you are out experimenting. you will have to just mess around, a lot, a whole lot, but when it clicks, it will be worth it.
There are 3 things you will learn to adjust to get the pictures you want. You will learn to do a balancing act between the 3, there is no "right" way to get a photo, and some methods are more of a risk, but can have a reward, but also can end with your photos simply not usable.
1. Shutter Speed. This is how fast the capturing happens. It is measured in fractions of a second, to many seconds. My D5600 goes up to 1/4000 of a second. It can stop helicopter blades, it will stop all motion and freeze things in place. As you slow it down it can get tricky as how you set it. i will have it at 1/100th of a second or higher if there is gonna be people in the shot. indoors this becomes an issue because the the faster it is set, the less time for light to enter the camera. this is where the importance of the size of the aperture and how much ISO will have to be used to be able to have a well exposed photo. Keep getting slower and the tremble in your hand, or the sway in your stance can ruin a picture. I have taken good photos at 1/20th of a second handheld, but will hardly bother if that's my only option. A good tri-pod is your best friend. Get the camera stationary and the shutter speed is not an issue, unless your shooting a moving subject. This is where you can slow the shutter speed down to having a capture take multiple seconds, minutes, or even hours. THE CAMERA REMEMBERS ALL THE LIGHT FOR THE DURATION OF THE SHUTTER BEING OPEN. Long exposure is how people get photos of light trails going down the road. I'll cover long exposure in a post of its own.
2. Aperture. These are the numbers on a lens that seem to be gibberish. At least when i started, they made no sense. f/3.5-5.6 is an example, and if you are new to DSLR's means absolutely nothing to you. I did notice that a lens with a lower f/ number, would be more expensive, sometimes enormously more expensive. Those numbers represent how large the aperture can open, which is profoundly useful, as the bigger the opening, the more light can enter, and in a shorter amount of time. This is key to be able to have a higher shutter speed. I now only use lenses that are f/2.8 or larger. The lower the number, the bigger the aperture, and therefore, higher the price. Take it from me, with photography, you get what you pay for, so do the research, this hobby is expensive, and I wasted money, trying to save money. Alternatively, in a well lit area, such as outside, aperture doesn't play as big of a factor, but the more it is closed, the larger the depth of field for things to be in focus. Closing it up is useful for landscapes and captures where you want more in focus. f/1.8 is so open, and with such a shallow depth of field that, in a portrait a person's nose can be in focus and their eyes will be out of focus. In my opinion, the lens is the most important tool in your arsenal, so spend the money there, and get ones with that lower f/ number.
3. ISO. This is your camera's sensitivity to light. when the aperture is open all the way, the shutter speed can't be safely lowered, the ISO is what will make up the difference. It wont completely boost an entire scene, but the light that is present. So, if there is only a streetlight in the scene, upping the ISO will just make the streetlight super intense and overexposed. Most of the time, ISO is only a last resort, as the higher it is, the more noise will be in the capture. Noise is the grain in a picture, it will take from the crispness of the photo.
These three things must be learned to use a camera to the most of its potential. Fiddle around, try things, take the same photo several times with these numbers different in each capture, see what happens. It's a balancing act between the three, and the only way to really grasp what each one does, i think requires just experience with them. So, go capture some stuff, make it blurred, make it freeze, mess around, and have fun with it.