If you like, you can try my non root smartphone guide which works with any Android phone from the last 5 years, and even upto phones as old as Android 7 Nougat. (NOTE: Please do not use phones that old for daily driver, they have security risks.)

https://lemmy.ml/post/128667

You can do 99% of the stuff fancy custom Android builds claim to provide without needing to root or unlock bootloader (this one prevents lots of risks alone), as far as privacy or security goes. Sure you may not be able to change your boot screen or use some fancy Xposed mod, but that is the cost of extra security. You can use Wavelet or RootlessJamesDSP without root instead of Viper4Android for sound improvements.

I do have a ranking of phone brands in there that is a bit old, but free of political biases, and still relevant. Your options for a LineageOS compatible phone might be low. Xiaomi and Motorola are good options. Avoid OnePlus if you want to use full 48/64 MP camera resolution, they lock it to their own app intentionally. https://www.celsoazevedo.com/files/android/google-camera/f/post-05/

Not sure what else I could tell, depends on whatever roadblocks you encounter upon research.

If you want a great cameraphone with bootloader unlocking, maybe buy a second hand Xiaomi 14 Ultra in few months?