Ok, so you have a script called /bin/script.sh - when you follow that with arguments like First and Last there are already variables built in to allow you to use them.
/bin/script.sh First Last is going to store the value of First in $1 and Last in $2 - so if you script contained something like:
#!/bin/sh
echo "Your name is: $1 and your surname is: $2"
you'd be closer to solving this problem.
EDIT:
Actually, this is pretty ugly - there's a fairly good introductory tutorial over
here.