@caesarologia If possible, install LineageOS on your phone. You will now have a blank slate.
From here, you'll want to install F-Droid as your app store (you can also add 3rd party repos to this if necessary)
For messaging, the obvious choice is Signal. Phenomenal app - I use it for all my messaging and calls.
Navigation, there are quite a few options, but it depends on your use case. Take a look at https://osmand.net/ and https://www.navmii.com/ for starters.
@UnixAnt @caesarologia Signal without gapps is working terrible on my phone. Often Messages are delayed, and calls can not be connected. :(