connect Android mobile to Ubuntu

[Ζεύξις Μπαξεβανίδης]

Am new to the Linux philosophy in general and unaware of how to use the 
terminal commands, which am studying now. It is not so easy for me in my 
age (74yo) but am trying hard. It would be extremely kind of anybody who 
could give me a answer on how to resolve my problem of connecting my 
phone to my computer. Have downloaded the KDE conect on my pc and my 
phone. My system is Ubuntu 19.10, device name user-Optiplex 7040, mem 
7,7 GB, gnome 3.34.2, processor 64 bit, disk720gb.