All my warning lights come on occasionally

Hey yall, first time poster, long time lurker. I have a 2008 Prius touring with 171,000 miles on it. Yesterday, I had a check engine light come on, so I went down to Advance Auto, borrowed a code reader, and pulled the code. Told me it was a #4 cylinder misfire. I pulled all four spark plugs, which were not iridium, and replaced all four. CEL went away. Then, I get in the car today, and all my warning lights go on, and the car won't start. I turned it off, then back on, and the car started, and I went on my merry way. What is this a precursor to, and how do I fix it?
Thanks

 

What might I be checking the 12v for, and what is the difference between a prius code reader, and a universal one? Thanks for the quick reply by the way!