i want to create a some icons for both web and mobile use adobe illustrator cc 2017

That sounds like a good idea. And if you're a CC subscriber, you should automatically get the 2018 update.

But did you have an actual question you wanted to ask?

You must prepare a draft. You have to do this drafting process mentally and then transfer it onto paper. You can take a picture of the draft you transferred. You can then open this photo in the AI program on your computer. After you open the photo, you need to do it from the tools that Adobe has developed for the program. There are many options for designing icons within these tools. You can design icons using only objects. Or pencil tool using organic or geometric icons from the draft you can make the design. There's no formula on how to do them. Generally, if you want to improve on this subject, learning the shortcuts is the first priority. With short paths will increase your practical count. He then has to construct the structure of artistic thought personally. You can look at the work of many artists. A good start in looking at the basics of design. Improving the visual thought pool will make it easier to use the program. Also, remember that every vehicle is designed to solve a lot of problems in proper use. This means that objects have many benefits, from designing a table to designing an icon. Try to comprehend the importance of the term anchor by practicing. You can create both geometric and organic shapes with anchor points of objects.