Organizing the Project Panel

I'm an 83-year old beginner at Premiere Pro.  Using Udemy instructional video.  Can't get project panel (lower left) organized right.  Ideally, you'd have 3 or 4 overall categories (sequences, videos, audio), and your clips would fit easily into those.  Somehow, chaos creeps in.  I find video clips mysteriously repeated.  The color-coded squares at each item's start seem to come attached randomly instead of indicating a set type of asset (e.g., shouldn't a Sequence always be the same color?).  I've looked all over for some detailed help, but the gurus apparently think it's so simple they shouldn't waste their time on it.  Does anyone know a video or written piece that addresses this?