I am going to .... is used to indicate a plan of action that can easily be changed.
I will .... indicates a future action that should not change. It is some to be done for sure.
Will ....
Will be ... ing ....
As with
She lived in China
She was living in China
I will watch tv
I will be watching tv
The only difference is context
I will watch tv means there is probably nothing important about it.
I will be watching tv when you get home.
There is a. Relationship between you arriving and what I will do (watch tv).
I am going to
I am going to be ... ing
The difference is only in context. In the top one we don't really know when unless it is stated.
In the bottom one the action will be in the middle when another event happens.
It will rain tomorrow.
It will be raining tomorrow when I get out of school.
Thank you 🙏🏻🙏🏻