Someone else will show up with the general rules.
They may have relaxed stuff or toughened rules since I flew, but I'd wear slip on shoes like your crocs. I used to wear my danskos, which have steel bars in them, ha, but still are slip ons.
Expect to empty pockets, take off watch if you're wearing one. (I lost a watch at Phoenix airport in this process, grrr, so place stuff carefully in the basket they provide. I put mine in my purse and it apparently fell out. I was watching, no one just snagged it.)
Your checked bag will be checked by them, if you did check it in. Your non-checked bag will go through the xray machine.
I don't know about food and liquids, wait for next poster. Last I boarded a plane, I had a latte purchased after passing security in my hand and probably a sandwich in my purse.
This is moderately exciting the first time. Less amusing if you change planes several times.
Ah, they showed up while I was typing, cool!