Not to be totally fluent, but decent at it. Like able to go to Italy and get by.
I also already have some background in Spanish which i know is similar to Italian in words and verbs and grammar, but obviously not the same.
Answer on How long might it take to learn Italian?
i?d say a year, to be able to have some fluency, of course it?s up to each person, italian grammar has a lot of details, a lot of verb tenses, then you have 2 ways to say something for example in one verb tense "ho mangiato" (i?ve eaten) but you have to say "sono andato" (i?ve left), also you have the differences between di/da, in/a.. Spanish has it more simple, however, having a background in Spanish will make things easier for you.Good luck!