Legal documents for data confidentiality

Do I need legal documents for data confidentiality? I have a nice new blog (less than 3 months old) and I am not able to collect emails because I heard that it was necessary to obtain a privacy policy document. a lawyer who is expensive.

I'm only posting content. And I do not know how to handle legal problems.

Do I need a lawyer for my blog? Do I even have to worry about it?