You got the following error:
tar: usr/local/src/scala/nano.bashrc: cannot open: no such file or directory
tar: Error is not recoverable: existing now.
because you didn't extract the contents of scala-2.12.1.tgz because of a typo error. Instead of:
sudo tar -xvf sscala-2.12.1 .tgz -C /usr/local/src/scala/nano .bashrc
The correct commands should be:
sudo mkdir /usr/local/src/scala/
sudo tar -xvf scala-2.12.1.tgz -C /usr/local/src/scala/
These commands will solve the immediate problem in the question, however it should be noted that according to the official Scala website the most popular way to get Scala is either using Scala through sbt, the Scala build tool, or to use Scala through an IDE. Using Scala through IntelliJ IDE is recommended for beginners who are not familiar with the command line. The free intellij-idea-community snap package can be installed in all currently supported versions of Ubuntu with the following commands:
sudo snap install intellij-idea-community --classic
In Ubuntu 16.04 and 18.04 the package name of the required Java 8 JDK in the default Ubuntu repositories is openjdk-8-jdk and it can be installed by the following command:
sudo apt install openjdk-8-jdk
Run the following commands to export the path to SCALA_HOME to the PATH variable.