files are not read using a for loop, because it'll loop on each element output, and you can't be sure of what you'll get.
instead, use a while loop, like this
while read cat_01 cat_02
do if [ "$cat_01" = "whatIwant" ]
then echo "$cat_01 is whatIwant"
this is very basic.
as there is only two elements per line, you could easily feed an associative array, and choose family or friends, or else, from the index.
searching the net you'll surely find other scripts like yours: agenda, address book...