This beginner unity tutorial will help understand the new input system.
I showed here several different ways it can be used as well as some unusual problems and their fixes.
You can use any of the methods showed based on personal choice.
But you should probably avoid using Send/Broadcast messages except for very simple use cases. As they have a more limited event information and can be quite slower than the other methods.
The most common usage type you see in videos are using the generated class and using unity events.
But using the PlayerInput component C sharp events is also a very valid choice that gives you a lot of control and utility.
CHAPTERS
0:00 Intro
0:06 Overview
1:25 Installation
2:28 Input actions
6:09 1. Generated class
6:22 Cube controller
6:30 1. Generated class continuation
12:42 PlayerInput component
13:24 2. Send and Broadcast messages
15:33 3. Invoke unity events
18:50 4. Invoce C sharp events
20:11 Using action maps
23:18 Assertion error and fix
24:34 Combination keys and shortcuts inputs
26:19 Consume inputs config
26:58 Enabling UI inputs
27:24 End