editing an updated project from cs6 to new cc, can't delete unnecessary clips

got new video editing laptop, Win 10, Adobe CC all apps. Everything updated, Premiere, Win 10, Nvidia, converted clips from MP3/4 to M4V.  Worked in CS6 for 6 years.  Now, trying to update old project and delete unecessary clips but can't.  any help on weekend from tech support?  Not from Saloni.