I second the people that said lineage OS. I am using it right now. I got this Nord phone because I knew they were easy to tinker with. I used it a bit and ended up with a newer galaxy. Well after I put lineage on the Nord every problem it had went away. Excellent battery life, runs smoothly, weekly security patches if I want etc. One thing that helped a lot was the "Aurora" app store. Let's you install apps anonymously from the play store without requiring google services. Many of them won't work due to the no google services, but a surprising amount of stuff does just fine even if it complains about it.