Spiacente is the present participle of the verb spiacere= che dispiace (dislike, mind, be sorry)sgradito (unpleasant, unwelcome):
It's an adjective meaning feel sorry (spiacente= che prova dispiacere= mi dispiace=I'm sorry). Who says that it's no really used in Italy he don't really know all the uses of the italian language .
This thread seems quite long and generally holds the same opinion that "Spiacente" is rarely used. It would be nice if one of Duolingo's experts could comment on this in particular because the phrase is presented very early into Duolingo's sequence of learning and therefore many more people in the early stages of learning the language are going to be confused by it.
'Il mio nome e Camila' would be 'my name is', while 'mi chiamo Camila' would be 'I am called Camila.' I know, it sounds awkward in English... but it's the same thing in Spanish. You can either say 'mi nombre es Camila' or 'me llamo Camila.' I am a native spanish speaker and I would normally say 'me llamo Camila.' I'm pretty it's the same thing for Italian.
As i understand it, you'd say "sono spiacente" when you're not really sorry but when you cannot grant a request. As in, "I'm sorry/I regret to inform you that we're all out of lobster" or "I'm sorry/I regret to inform you that we've chosen someone else for the job". Mi dispiace is an actual apology