I tried Ubuntu long before I ditched Windows completely. I didn't then and don't now like the colour scheme. On top of that I find that the way the menus work is off putting. I tried lots of different types of Linux before I found one that I liked all round. That one is Mint with the Cinnamon desktop. The main difference is the colour scheme which better suits our pale Northern vistas. Mint is actually based on the Ubuntu system but revised. The 'Start' button is called 'Menu'. You still have the task bar on the bottom of the screen which shows which programs are running and the Menu and sub menus work pretty much as they did in classic Windows. I didn't recommend it because the Cinnamon desktop is considered resource heavy so it's not the best for an older machine. Zorin is lighter and smaller. It is not as small as Puppy but I never got the internet working with Puppy and gave up after only an hour of trying.

One list of most popular Linux distributions starts

Ubuntu
Mint
Debian

Puppy comes ninth and Zorin doesn't even show. I prefer and use Mint but for a light, or old, machine user I would recommend Zorin because it is small and you can tweek the way it looks. Whichever you go for, if indeed you do, remember that they are all free. They all get updated but there are no automatic updates. There is now an enormous amount of free software and none of the Linux systems have the Windows vulnerability to virus infection.