First of all you should decide; do you blog for pleasure or as a business ? Because, Global Data Privacy Rules changed in 2018, and if you haven't checked in on your Blogger / Blogspot Privacy Requirements for a while, then,you must-read this article. Blogspot doesn't require you to have a Privacy Policy in all circumstances.
İf any website demand and collect personal data must have a Privacy Policy. That could even include your Blogger site.
If you
use Google Analytics, add third-party links, or collect any data, then a Privacy
Policy is a legal requirement, part of your vendor's Terms of Service.