freezing and others

I’m doing what I feel might be a complicated thing for Premiere. Or at least, I’m thinking that because I’m starting to get freezing and other problems again. This happened with my old computer, but since I have gotten an SSD with plenty of room as well as the regular good hard drive, I’ve not had that problem. I’m thinking that maybe I should be rendering, though I’m not sure what that is for. I dimly remember it from a year or two ago.

I’m doing pic in pic for several clips in my song—perhaps about 5. So my first  question: if I have put in the crop tool into one of my clips—in order for it to fit better with another clip on the other  side of the screen—and I later want to go back to that area to crop it a little differently, I can’t seem to access those cropping properties. So, what I’ve been doing is simply re-dragging the cropping tool back into the clip, which makes the cropping properties visible on the R side of the program view. Perhaps I’m introducing too many layers here, and there is a more appropriate way to call up these cropping properties into a clip that’s already “crop enabled”-if  that’s the expression. I tried double clicking on the clip, but that didn’t work, nor did right clicking.

2)what I’m getting now is sudden stopping of the contents of the screen. The music track, which is just audio, keeps playing, but the timeline and the video just stops. In fact, I can’t even stop it, bc it’s frozen in the play mode, and there is no pause button visible. Yet the music goes on!

I’m thinking that perhaps there is too much edited material out there, and I’m supposed to render—but that’s just a wild guess. Any ideas.

LNovik