Do I need a privacy policy?
Almost certainly, if you collect any personal information at all, including email sign-ups, analytics or cookies. Laws such as the GDPR in Europe and the UK and the CCPA in California expect one, and the Apple App Store and Google Play ask for a privacy policy link for every app. Even a site that collects nothing benefits from saying so plainly.
Make it match what you really do
A policy is only useful if it is true. Before publishing, check every service you use, including analytics scripts, embedded videos, fonts, chat widgets and payment buttons, since many of them collect data. If you add a new service later, update the policy and the date at the top.
Where to put it
Publish each document on its own page, such as /privacy and /terms, and link to both from your site’s footer, sign-up form and app settings. App stores ask for the privacy policy address when you submit an app, so keep it at a stable link.