First set the spool tension. Tie whatever lure you plan to use on. Then release the spool allowing the lure to go to the ground (or your baot deck). Adjust the spool tension so that when the lure hits, the spool stops letting out line.
Then set your magnetic brake to the highest position (10 on some reels). This will limit your casting distance but will also minimize backlashes. As you get better at casting you can ratchet the magnetic brake back.