Clear display and other Commands for Serial LCD problems

I have a 20x4 Serial LCD from Spark fun that I’m trying to get working with an Arduino. I’ve got it working sort of. I can see the characters on the display but can’t figure out how to get the commands for “Clear Display” “Set Cursor Position” etc. I’ve looked at the V2.5 PDF on the site and the HD44780 dtatsheet but don’t seem to be putting it in the software corectly. I’m using ```
Serial.Print


Thanks Steve