I am using Android Studio 2.3. and I don't see padding attributes. Neither I see dimens folder in my app structure?

Android Studio (AS) 2.3 will look different to what you are seeing in the videos. I am assuming you are looking at the Design view for your xml files.

Once you have clicked on a design element, the Properties panel will appear on the far right of your Android Studio window. At the top of the Properties panel you will see two opposite facing arrows (they are probably blue). Hover over these arrows and you will get a small hint that says "View all properties". Click on these arrows and you will be taken to all of the properties. Scroll down to find the property you are looking for.

With regard to dimens folder. A this stage of your learning it's a file, not a folder. In AS 2.3 you will need to create this file yourself. It's not hard.

In the Project Directory tree panel on the far left of the AS window open the directory tree to App -> res -> values. Right click on values directory and select New -> values resource file.

For the File name, type "dimens". Then select "OK". That's it. AS will create and initialise the file for you. It will be obvious what to do from there.

Hope this helps. Any problems, just ask.

After I added a new values resource file named "dimens" I got this error when I tried to run the app:

Error:Execution failed for task ':app:mergeDebugResources'.

C:\Users\user\AndroidStudioProjects\FunFacts\app\src\main\res\values\dimens.xml: Error: In DataSet 'main', no data file for changedFile. This is an internal error in the incremental builds code; to work around it, try doing a full clean build.

How can this be fixed?

Thanks!