Answer 1

If you're using Eclipse, go to help -> marketplace and search for WindowBuilder

Get the plugin then go to new -> other -> search for window builder

Below your code you'll find the design tab.

Answer 2

Also it would be very and very useful if you will use Java in mobile development. It is very important for American IT. If you want to learn Java mobile development:
1. Learn basics of Java;
2. Download Android Studio and Java SDK (Set Development Kit)
3. Learn these technologies;
4. Profit!

Answer 3

Okay

Answer 4

using netbeans