Is it possible to have multiple languages?

Is it possible to translate articles in another language and enable the person to choose their language on the website ?

Yes, you can use dynamic translation services such as Weglot or Localise

They are slow and expensive IMHO, and you also have very little control over the translation. For Italian Spaziocrypto I created a static translation using DeepL. Separate Ghost sites with automatic translation and publishing. Additional eight languages in the works - JP/SP/CH… Get in touch if you want to discuss.