Disco or Nightclub?
Disco offers you the option (from left to right) to get a client (for pimping jobs), a cougar (gives some excitement and maybe some money) and a girl (for iSnatch book -> recruit fuckbuddy).
Behind these option you can tell the 'secret' password to the bartender to get some random drugs and buy/sell drugs (which can be used for parties).
The password is an anagram of words in your GUI language (English tits, titties, hooters, tequila, whiskey).
Nightclub consists of two games. The first is the party option where you can visit a party of some else (gives random girls, max 5) or throw your own bunga, bunga party (here you need hoes, alcohol and drugs. The outcome depends on your actions and can be several dozen of girls and some high paying clients).
Second option are the Madame Edna jobs which count for pimping league and level up your hoes. With the last option there you have an overview about your current deals (attention they are valid only 7 days. Then they are gone and you get no money;-)