Asset Script issue

After upgrading to the latest version of Unity, i restarted my project, due to conflicts with assets and old scripts.

Even before i started, i got stop errors that i need help in resolving (see attached file) any help would be greatly appreciated, as I was so close to creating my game.

I’d try updating the Timeline package first.

how or where do i go to update?

Window/Package Manager

how or where do i go??

then do i call up the timeline script ?

Packages are managed using the package manager

https://docs.unity3d.com/Manual/upm-ui.html

Go to the menu Window, then select Package Manager. Make sure you have the latest packages.