For the first question, you would just add the parenthesis to the string mutation1:
String word = "sadly";
String mutation1 = "(" + word + ")";
For the second you need the method substring from the String class:
It is defined as String.substring(begining, ending);
String name = "Smith";
String firstCharacter = name.substring(0, 1);
0 is considered the beginning of the string, then you get the next 1 characters.