Well, the basics are,...
Aperture -- the opening of the lens. Expressed in units called f stop. The larger the number, e.g. f22 the smaller the opening of the aperture. The smaller the number, e.g. f1.8, the bigger the opening of the lens aperture. Bigger opening means allowing more light to enter and exposed to the sensor.
Shutter speed -- the time taken to open and closed the shutter of a camera. Usually expressed in seconds or fraction of a second. eg. 1/100 seconds. For FF sensor without image stabilizer, at between 12mm - 80mm, our hand movement usually will not be captured for as low as 1/60 sec. Anything slower, with not so steady hands, will give you blurry pictures. The longer the lens, e.g. 105-600mm, the more prone the camera is to handmovement... so faster shutter speed has to be taken into consideration, e.g. 1/125 or 1/250 sec.
ISO -- traditionally known as sensitivity of the film to light. Modern digital photography ... simply is trying to make is as close to traditional film photography, therefore the term ISO remains. The function is, to be able to be exposed to light as quickly as possible and capture as much info as possible. By using high ISO sensitivity setting, it means you can push shutter speed faster at the same aperture opening to achieve the same exposure. But the con of higher ISO is... the sensor is exposed to the light at too short a time, and will not be able to capture sufficient info for the exposure, hence the noise you see on the image where the processor tries to interpolate what is in between to complete the image.
A tripod basically helps to alleviate camera shake in slow shutter speed. Because the camera is set on a tripod, there should be little movement. That's why you can use a small aperture to capture more depth of field, at low ISO in low light (low EV) with slow shutter speed (e.g. 1sec or even as high as 30 secs).
Bulb setting means the shutter is open indefinitely as long as you press on the shutter release button and hold it there. The shutter will close when you release the shutter release button. It is not possible not to cause any movement to the camera by pressing and holding the shutter release button. So, the use of remote release cable for Bulb is necessary, on a tripod. Of course for creativity, you can hold your camera by hand, turn off image stabiliser and user bulb and move your camera around to create some artistic image of some light.
I hope you have a better picture of how a camera works, in a nut shell.