Instruction manual for each feature (page by page) on my web app? (instead of tooltip)

Problem:

I'm designing a web app that has features that people are not familiar with (learned this through user testing).
I need to guide users through, like hand-hold them, telling them what this page is for, what this term means.

For example, there will be a page called "Goal setting." Users can write goals and key initiatives that contribute to each goal. users don't know the difference between goals & key initiatives.

Some possible solutions:

1. Tooltip
but I'm opposed to it since it won't be a quick tip)

2. Chatbot
- e.g. Intercom
- it is non-intrusive
- but it might get expensive

3. Standard side sheet Google Material's example
- it can contain some long-form information as I intend to
- but I don't have the top app bar in my app to anchor this side sheet onto

I'm leaning towards #3. If anyone has any decent examples of this or other ideas, I'd love to know!

Thank you so much :)