Structure of a find command:

find where-to-look criteria action

$ find . -name "*front*" -print
#=> print out files that contain "front" in the current directory
$ find / -name foo.txt
#=> find a file called foo.txt from root

To avoid permission denied use the following:

$ find . ! -readable -prune -o -name '*.txt'
#=> find all readable .txt files from current directory