#german syntax

Hi! The former is right. It’s because you’re specifying the place before you specify the weather. If you talked about the weather first, the word order would be “normal”, i.e. es ist kalt in Berlin. 

Hi! You seem to already know where to put the adverb in the sentence. If you use sehr it usually comes before the thing you want to stress, so in this case the second adverb gern. This is a specific case, though. Generally, I’d say try and figure out the relationship between the adverbs. You don’t have a lot of them after one another very often anyway. But if one of the adverbs describes another, then I’d say put it before it, like with sehr.