There is no much difference between Italian and Spanish. If you know Spanish you can learn Itnalian easily.
If you know Spanish well that may make Italian a bit easier to learn due to many similarities.
It is your choice whether you want to learn Italian or French, but I would say that you should learn French. The app or website "Duolingo" helps a lot in learning a new language, even French! You should try it.
French: https://www.duolingo.com/course/fr/en/Learn-French-Online
Italian: https://www.duolingo.com/course/it/en/Learn-Italian-Online
I have to agree with most of the others. If you already know Spanish, then Italian will be a breeze for you to learn. They are basically similar in many ways. French is a whole different ball game and I think it's much harder to learn ! Buona Fortuna !
I would go with Italian! I love the Italian language!