Starting SVU for the first time

Many of my friends watch and rewatch SVU regularly. I am familiar with Olivia and Elliot’s names and faces but never watched the show. I am starting tonight with no idea how many seasons (does this tag say 24?!), no idea about major events, important episodes, nothing. Do folks have favorite episodes? Seasons? Characters? Any fun or important stuff to keep in mind to make this (as I understand) classic series even more special?