rx300

Hi, I'm also new in this forum. I just bought a used 2002 2WD and would like to change the oil myself with Mobil1. I think I found the filter but not sure where the drain plug is. I checked underneath and found a bolt and an allen type. Which one is for the oil? I also read that the gasket should also be changed. Where could I get it besides the dealer? Appreciate your help. Thanks.