What To Bring On A Flight?

So, in a couple of weeks, I am heading to San Jose, California with my Dad for a conference and to meet up with a good friend of mine. This is the first time I’ve flown since 2004 and I found the TSA’s guidelines to be a bit too confusing, so I thought i would ask here.

What are the guidelines for what you can and cannot bring in your carry on for a flight on Southwest Airlines? Any advice and suggestions and tips would be greatly appreciated.