Now you have launched Jupyter Notebook. Let us a take a look the User Interface of Jupyter Notebook and understand how we can interact with it. After starting the Jupyter Notebook, you see a page like this in the browser except the highlights which I have marked to describe the functionality of them.
On the page, you are viewing in the browser has various information. Block marked with 0 shows the list of directories and files present in the current directory, you may navigate to the directory of your choice.
In this block, 3 denotes the current working directory, and each breadcrumb is a link to a directory so that you may navigate directly to it.
If you click on the New button, which is at the right top of block 0; You see a pop menu (block 1) which enables you to open a new notebook with Python 3 (block 2). Since we have installed Python 3, it is showing Python 3 here. Click on Python 3 link and open the new Notebook page.
On the top of this notebook page, it has a file name (block 0), to rename the file click on it, a new pop dialog box like this will appear.
\You may give it the name you want to give to this file. Moving further to block 1, which is a series of useful buttons.
Below this menu, there is a working area containing cells. A Cell (block 2) indicated using blue color with In  prefix is input cell in which we can write programming statements. If the code in the cell is not correct, then the interpreter will give you an error, e.g. block 3. If the code is correct, then it will provide you with the output (block 4 and block 5).
Next, to the menu, there is a drop-down menu (block 8) which lets you change the behavior of the cell. Block 6 and 7, are marked as a non-programming statement. If you need to write any comment in the notebook, then this is helpful.
Spend some time with the Notebook, so that you get familiar with the tool we are going to use throughout the series of learning Python.