Yes, you have to use 'to' in these questions. It is not possible to omit it. You go TO a place. The only exceptions are when you use 'go' with an adverb such as 'upstairs', 'downstairs', 'away', 'abroad' and 'home'. These adverbs include the idea of movement in a specific direction, so there is no need to use 'to' with these words. But if you name the place (the name of a town, country etc) or the type of place (a butcher's or a school or an airport), you always need to indicate movement with a preposition before the place. You also don't need 'to' is if you use the word 'where'. This is because 'where' includes the concept of movement towards a specific location. For example, you can ask "Where did you go?" or "That's the place where I went." I hope that helps.

Yes you need to include "to". Also, please be careful about the apostrophe and plurals. "Which butcher's did you go to?" could mean "Which butcher's shop did you got to?" This is only one butcher's shop. OR "Which butcher's shops did you go to?" means you went to several butcher's shops. It is better to ask "Which butcher did you go to?" for only one/singular, or instead ask "Which butcher's shop did you go to?" Same for ...florist's shop. "Which florist did you go to?"