I remember these being suggested to me as a newbie a long time ago.
Please continue to learn! It's great to bring new perspectives to play.
I kind of answered this elsewhere in the thread, but here is my answer to you.
If you are referring to basic OS level functions, they are super similar, but they are also wildly different.
Ubuntu is based on Debian. It is centered on keyboard and mouse input, often with touchscreen. It uses a Canonical kernel.
Android is its own flavor of Linux, entirely centered on touch input. It uses a heavily customized AOSP kernel.
While I think it might be entirely possible to install and remove packages to have one act like the other, they have wildly different kernels.
Here is a pretty lengthy write up on the subject by Richard Stallman.
https://www.theguardian.com/technology/2011/sep/19/android-free-software-stallman