Opening a console
SonicDE comes with the console application Terminal. Any other console application, such as xterm, will do just fine too.
Why?
When you ask for help, you may be told to "open a console" or "open a terminal", which mean the same thing. Why would you want to? Sometimes something doesn't behave as expected. When you use a graphical interface to do something, you don't know why it failed. If you open a terminal and try the same thing from the command line, you get a lot of text showing what the command is doing, and what went wrong.
How?
There are several ways. Open the application launcher and search for "terminal", or look for an entry with an icon like a black, blank screen. Click it and your console opens. Then type the command your helper gave you.
You can also press Alt+F2 to open KRunner, then type konsole and press Return.
Note: If someone tells you to type a command, take care not to add upper-case letters unless you're told to. Linux is case-sensitive. If you add an upper-case letter where there shouldn't be one, it probably tells you there is no such file.
Later, as you gain confidence, you may use a terminal more often, as some things are much faster from a console. You needn't worry about that at first.