I think Google is the best. Got translate function

我学中文两年了 我学了两年中文 Are both fine. None of them implies it's stopped 了 only indicates status has changed, might or might not be finished. 过 indicates this thing has been finished.

What's the English?

Would be easier if you post the English sentences with the Chinese.

我没有熊猫(没有 on it's own means none, unless you use 2,3,4 or other number. Even if you do, it would be better to say 我没有五只熊猫那么多/我没有那么多熊猫) 我一只熊猫也没有（if you want to highlight that ONE） 你们喝不喝果汁 In English you might do need to add all to this question because you can tell how many people there are but 你们 indicates you are asking the group so just 你们喝不喝 is fine. If your question was 'are you all going to drink juice' or 'are you all fine with juice'. Say 你们是不是都喝果汁？/你们都喝果汁吗？

Second one is a bit weird