Is Brazil Portuguese or Portugal Portuguese more useful to learn? Are they different?
Well, as a native Brazilian and a person who studied Languages, I can say that both of them are 99% equal - I'm not sure a version is more or less useful than the other as for learning (why not learn both? ). The only major differences I see is in pronunciation (stress) and that some words mean different things - but that also happens with AmE and BrE if you compare.
Portugal uses the pronouns 'tu' and 'vós' which we Brazilian people almost never use unless in very formal contexts or situations (if you come from Southern Brazil it's likely you'll address to people using 'tu' and not 'você'). PT-BR also has some words which are spelled differently from BR-PT (most of them is with a mute 'C').
These sites may help you further:
This is just my opinion, I know nothing about Portuguese but I think Brazilian Portuguese sound better. European Portuguese sounds like Spanish with a Polish accent. Brazilian is also spoken by a lot more people, Portugal is a really tiny country. Most resources I've come across that teach Portuguese will teach Brazilian instead.
But I'm sure the information Alma gave you is better, since he is from Brazil and I'm just an American ^^