Visiting Kochi - need ideas and recommendations

I am visiting Kochi for the first time from Mangalore for a friend's wedding the weekend of Feb 16-17. How many days are needed for a decent Kochi trip. I could likely extend my trip by 1-2 days. What would be the must see places - even if they are non touristy/off the beaten path. I love little cafes/coffee shops and any bookstore recommendations. Anything that has a relaxing vibe. Also curious about (silent) meditation retreat centers. I don't speak Malayalam, would language be an issue?