When you are ordering food at a restaurant Molim Vas is polite way of saying things.... it's something like (onegai) pleas. Because of Vas it is formal, if you would to say Molim te. .....that is more informal way of saying please (it's usually said between friends). Želim = I want or I desire....It's common. Imate li ? ( Da li imate xxxx?)= Do you have xxxxx ? It's formal and common. Rado bih....this one is a bit tricky. You can say that but is sounds archaic and although it is very polite it's too polite in daily speech. This tense is called Aorist ( i think :) ) , so you can look it up. If you can imagine situation in which you play a role of princess this would be tense in which you would speak. Ja bi(h) svinjetinu. or Svinjetinu molim Vas. It's common way to say I would like to have pork.