Drawing a cartoon gold fish is not necessarily more challenging than drawing a normal one. You just need to choose the right colors (in this case, a couple of orange tones) and draw all the appropriated fins accordingly.
You'll need to sketch many triangles and rectangles to illustrate your simple fish in this easy tutorial! Also, notice that I have drawn the tail a little bit lower than the body to give a special look to my character.
You should not have too many problems with this tutorial if you look carefully at how the shapes are placed in the drawing! I hope you will have fun drawing this cute animal and remember to practice every day to improve the quality of your work! It's the only secret.