How to promote a free workshop? What thoughts should I practice?

I know that free workshops need to be promoted as well, as people give their time and sign up.

However, last time I failed, no one signed up. I’m sure I couldn’t get the message to enough people, but I don’t have a vast network or many followers.

Now I don’t know what to focus on, and my thoughts are around why it won’t work for me.
C: free workshop coming, promotion needed
T: no one will sign up
F: defeated

Which would help more, but I don’t honestly believe it:
T: the right people will see my message and will sign up
F: motivated

I want to find thoughts that help me stay motivated and inspired, and I can believe them. I need help here.

Thank you for your coaching on this.