While things will be eerily quiet, you will still be able to find taxis. They won't be as plentiful, but they will be there. Especially at train and bus stations, there will be looooong lines for them and you'll have to wait a while.
Many places will be closed, sure, but you will still be able to enjoy yourself. Just in a muuuuuch quieter city. You can find good restaurants, still go to tourist places, etc. Don't worry too much.