Example:
if function1(input) && function2(input) {}
In this case would function2(input) be executed if function1(input) returns false?
What you are asking about is called Short Circuiting, and yes, Go does it.
In the language spec, it says that
Logical operators apply to boolean values and yield a result of the same type as the operands. The right operand is evaluated conditionally.
This means that, in your case, if function1 returned false, function2 would not be called.
No. Go uses standard conditional shortcut logic - the first false result in a string of && conditions will stop evaluation of further conditions (because it cannot yield a true result no matter what the other conditions are). Likewise, the first true result in a string of || conditions will stop evaluation because it cannot yield a false result no matter what the other conditions are.