Where can i find this node?

I am following a book and it says i need the “SET” node but theres so many set nodes i dont know which one is the one i need. I am attaching a pic so you can see which node im talking about.

You drag connection from blue pin, then you write name of variable. Or drag variable from list of variables on the left. Generally you need reference to variable, if you try place it in editor grid it will ask you if you want get variable or set it.

If you still can’t find it after Nawrot advice go into the actual MyCharacter blueprint.
Look for the Hero variable, in the list of variables on the left hand side window pane.
Then Drag it (hold down left click) and drag to the right directly into the main graph.
Then use Ctrl+X to cut it out of there, and return to the first tab with the BP above.
Then paste it using Ctrl+V. (If you’ve loads of assets finding variables can be tricky).

Go into your Blueprint character, for example “FirstPersonBP” or “3rdPersonBP”.
Then when you go to the “Graph” tab you see on the left side “Variables”. THis “SET” thing is a variable, you can set the variable from 10 to 50 by clicking a button.
You need to create a variable and then drag it to the graph and use “SET”