What is the best and most simplest way to make it a locked down phone

Feed it to an industrial shredder? No, seriously, because …

avoid tracked and monitoring by officials and corrupt officials… Like I have beef with local corrupt feds level.

This is called an “advanced persistent threat” (APT) in military computer parlance. Advanced because they can bring almost limitless resources against you. And persistent because they can attack you 24-7 to find a flaw in your security. You on the other hand need to sleep.

“Best” and “simplest” are almost mutually exclusive for threats from state-level actors. For example, your phone’s radio could have been compromised at the point of manufacture; maybe unlikely, but very possible. Also, even if the radio is fine, you can still be tracked by the cells and Wi-Fi networks to which you connect. Some basic OpSec might get you good return on your investment, but still no match for an APT if you have a smartphone with you.

I’m hoping someone comes along with something meaningful. I’m in my de-Googling journey, but I know a couple things about OpSec and computer security. And it’s a game of rock, paper, scissors. Consider asymmetric tactics.

Edit to add: if you need secure electronic communications, consider something like Briar for your trusted circle. Decentralized, peer-to-peer, E2EE.

Edit #2: It sounds like you might have already been down this path, but just in case you haven’t seen this: https://ssd.eff.org/module/attending-protest