A tie is a curved line which connects two notes with the same position on the staff. The tie tells you to tongue the first note only, and to hold it for the length of both notes. Using a tie is the only way of indicating that a note is to be held across a bar line.
Play the F note and hold it for six beats.
This song contains ties both within one bar and across bar lines. Take it slowly at first and remember to keep counting to yourself as you hold tied notes. If you have trouble with the timing, clap the rhythm along with the notes.