Cannot install dependencies on ubuntu

Hello, I’m trying to install python 3.6 on Ubuntu. I read other forums. I’m having all kind of issues. When I run any python commands I now get ‘ModuleNotFoundError: No module named ‘gdbm’’. My real question is what is the easiest way of getting all the dependencies and which distro do you recommend for it to make it easiest?

Also as a side note, I tried using docker and python venv and I ran into other issues with both. I really would just like to install and run it in the normal way. Is there someone that can help me with this??