Updated: Mar 23, 2019
Unity.com to download
[Unity 2018.3.9f1] is all you need to install to get starting
You need to create 'Unity ID' to run Unity for the first time
(You can run offline after that)
All the tutorials [Learn]-[Basic Tutorials] and [Tutorial Projects]-[Roll-a-ball] are good tutorials to start for the beginners
You also need a microsoft account to activate [Visual Studio] to start editing scripts.