I meant dampening.. Also muting.. If the technique is still not familiar to you, it's the process of stopping unwanted noise from other or all strings..
These are thing you'll learn later on. For now work on getting clarity in your chording technique. Sometimes you just have to move one finger a tiny bit one way or another..
One note, one chord, one step at a time..
Have you started the fundamental lesson..? If you note what lesson you are on, it will helps us help you.
good luck