"Arguing that you don't care about the right to privacy because you have nothing to hide is no different than saying you don't care about free speech because you have nothing to say. "
Whilst this guide is not about Privacy but Security there are times when the two overlap.
Internet Privacy is overlooked by most users but its a right being degraded and fought for. Not only is there a multi-billion dollar industries that takes advantage of the lack of knowledge/interest of the general public selling their information and data but software/hardware, ISPs, Governments take advantage of this too. I highly recommend you learning more about Internet Privacy.
Check out these areas for a detailed guide on privacy:
https://spreadprivacy.com/privacy-tips/home - DuckDuckGo's Privacy Tips
https://ssd.eff.org/en/playlist/want-security-starter-pack - Electronic Frontier Foundation
https://privacytools.io - PrivacyTools.Io