How to stop apps from auto-loading at startup?

[LSMFTT]

OS = Nokia 3.1 Android 8.1 Oreo branded "Android One".
I can't find any function in my phone to disallow some apps from auto-loading at phone boot startup. I'm want to control which apps load at startup because some are infrequently used but are always running in the background using resources. Is such a thing built into stock Android, or do I need another app for that function? If another app is needed, any suggestions? Thanks.

 

[Mooncatt]

You are best to not worry about it. When it comes to memory, it uses the same amount of power whether it's used or empty. So what android and other modern operating systems do is fill it with the most commonly used apps (or even less commonly used ones if there's enough memory to spare), which stay dormant until called upon. They don't use any additional battery power, and multitasking is more efficient. It actually saves battery power by not having to initialize apps from scratch every time you open one.

There are memory optimizer and booster apps, but they are not recommended. When it clears those apps from memory, the OS is going to initialize more apps to fill that memory again. The optimizer app clears them, the OS adds them, lather, rinse, repeat. This leads to increased battery consumption because those optimizing apps are in a constant fight with the OS.