Your question has already received very good answers. People will understand you either way, but it’s best to say “take a shower” in American English, as some Americans may misinterpret “have a shower”. I’m just going to point out some general rules of English that we use almost every time we open our mouths:
1. We never follow a preposition with a verb in the infinitive. A preposition is always followed by a substantive noun, for example, the gerund: “difference between to saying”.
2. To form a question, we use inversion, so we don’t say “It’s any?”, we say “Is it any?”
3. For your question, we don’t use “it is” or “is it?” (equivalent to Spanish “es” or “está”), rather we use “there is” or “is there?” to talk about existence. (The equivalent in Spanish is “hay”).