when i type simple code such as Debug.Log("hello "); it says too many characters in character liter

Pls help i am using vs code and also vs code not showing unity stuff im new and know nothing . I tried editing preferences but still dont work

This may help you with intellisense problems:

Also, try update the VSCode package inside of Unity: Window → Package Manager → Search for Visual Studio Code Editor → Press the Update button

Also, this: No suggestions in Vscode

Also, here is how to report your problem productively in the Unity3D forums:

http://plbm.com/?p=220

How to understand errors in general:

The error message typically means you’re using a char value instead of a string value.

Are you typing Hello or Hello? The double/single quotations matter. Double-quotations represent a string literal, while single-quotations represent a char literal.
Since a char can only be one character long, Hello would be invalid syntax.