Yw: Good OPSEC is principle based. You are already ahead of the game by knowing it's super important to learn best OPSEC practices if you are going to use technology in the world we live in. 

Just remember it's all about YOUR specific threat model. There are basic practices, yes, but most people are not running from the gov (which is very hard to sustain for any extended period of time). 

Most people don't need to go full-on ghost or have a most extreme threat model. If you sacrifice too much convenience when it's not necessary, you will burn out. 

You have to take inventory and decide in what areas of your life it is more important for you to sacrifice convenience for extra privacy and security and to what degree.

Take your time. Go at it steady. You don't have to know everything to get started. 

 Re: overwhelming, start with the basics; a foundation.  Once you understand the UNDERLYING TECH, the rest, is much, much easier to understand.  Book I wrote (2001?) ... to get newbies to understand PGP (public key cryptography; what runs pretty much everything under the hood.  Download (free):  https://mega.nz/file/jsplULpR#4K6CmI1YqCSRZhiAj83hRHqi9DBpTkdIt0hWzilV3v8 Read chapters 3 (PGP) and if you want to go full cypherpunk, chapter 4 also (remailers). Chapters 1 and 2 were written back when no one understood the very basics of online security (thus are unlikely to be of personal relevance to you, you'll already get that bit).  You can cover to cover the entire book in around 1 hour 20 minutes (tops).