Sure. Things exist now. But at one point you didn't exist, and at a point before that humans didn't exist, and before that dinosaurs didn't exist, and before that life on this planet didnt exist, and at a point before that the planet didnt exist, and at a point before that out star system didnt exist, and at a point before that our galaxy didnt exist, and at a point before that the universe didn't exist. At that point, nothing existed.
Now since science doesn't prove naught, we do not prove nothing existed. We do experiments and analysis and other science standards to try and prove what might have been there before there was no universe. When those test and experiments, etc. come back with nothing, the scientists and researchers begin to theorize the idea that maybe there was nothing. Absolute nothing. There is lots of research, some of it posted in replies to you, all of the utensils you need to paint your picture. Pro tip though, maybe clean off some of that pallette and canvas you have. I think your so full of paint already that nothing else will get through.