LTspice (a free download from AnalogDevices) is excellent. It does have a steep learning curve, but that's well worth the effort. Many members here use it. There is a good Help section, a user group at groups.io, many online tutorials.

I’m going to start using this with my Mac and wondered where I can get other digital component libraries from such as for timing chips?

 

The user group has free downloadable libraries. Member @Bordodynov has an extensive library too.