I tried to write a simple sentence and go it wrong! I wanted to write, I made soup today. It was chicken and vegetable .I typed 'Hoje, eu fiz sopa. Ela foi frango e vegetais. This was wrong but I don’t understand why - was changed by google translate to Era fringe e vegetais. I thought Era was future?
Olá, @Linda.a.cook 
Nothing wrong with the verb fazer in your sentence. Your question is about the verb ser, which is the one that Google Translate changed from the simple past foi to the past imperfect era (not the future, which would be será). It does sound more natural to use the imperfect there. You should also add a preposition: Era de frango e vegetais (literally, “It was soup of chicken and vegetables”).
When talking about the past using the verb ser, the past imperfect generally fits better than the simple past, but it’s sometimes difficult to explain why (it also depends on the context). In this case, it helps if we compare the first phrase with the second. In “Hoje, eu fiz sopa”, the simple past is used for a very concrete, finite action that started and ended in the past and doesn’t have any continuity to it. Once you make soup, it’s done. On the other hand, in “(ela) Era de frango e vegetais”, the imperfect is used for an ‘action’ with a vague timeline, which starts in the past, but lasts indefinitely. When does it stop being chicken & vegetable soup?
So, in short, since the verb ser is generally associated with attributes or states rather than specific actions you can time, the imperfect is often perfect for it (I bet @joelrendall would come up with a better pun).
In addition to @Joseph 's remarks, my recollection of G-Translate is that it will default to Brazilian - at least that’s my recollection - I stopped using it a long while back. My recommendation is http://www.linguee.pt
K-so - begs the question - what are some (good?) PT puns? English being rife with them, I’ve been curious as to how other languages might handle the word-play.