Some apps I’d consider essential:

• URLCheck for better control when clicking on links
• Termux for a terminal emulator
• Tasker for automations (it’s a one time payment)

If your phone only has Google’s gallery and files apps do yourself a favor and get some third party apps for these things. I use Fossify Gallery and Material Files but there are many alternatives.

And here’s a good list for everything else: github.com/Psyhackological/AAA