I am moving across the country in 15 days, how do I start to pack?

I move December 1st and I have moved out of state before but never this far. Due to the stupidddd airline prices for 2nd bags and over weight bags, I assume I will be shipping probably 3–4 70ish pound boxes and bringing 1–2 bags on the plane. I am buying most of my apartment stuff there, so it’s not like a need a mover. But I do need to pack up my entire life (clothing, art supplies, small decorative objects, shoes!!, etc…).

Does anyone have any suggestions on where to begin? I normally enjoy this process, but I am worried it is a little to early to really start.