'Very' translates the Portuguese 'muito' before adjectives and adverbs. For example, 'very big', 'very old', 'very' expensive, 'very good', 'very well', 'very quickly'.
'Much' translates the Portuguese 'muito' or 'muita' before nouns (substantivos), especially in questions and negatives. 'How much?' is 'Quanto?' For example 'How much money do you have?' 'Do we have much time?' or 'I don't have much information.'