The pig script is in folder Pig, the sample data is in folder sampleData, since you have pig in the virtual machine, you should have $PIG_HOME.
load the data file into hadoop file system(not the local directory!) and put the script in $PIG_HOME/bin, then run this command
./pig -param input="/user/biadmin/sampleData" -param n=2 picture

where picture is the name of the pig script and 2 means "top 2", "/user/biadmin/sampleData" is the folder where the input file resides in the hadoop file system.