You could use 'going to' in past, present or future continuous forms. I was going to... I am going to... I will be going to...

When we use the present continuous (example: "I am eating dinner"), it indicates an action that is happening at the current moment. When we use "going to" (example: "I am going to eat dinner"), it indicates an action that will happen in the future. Using "going to" is a more common and colloquial way of saying "will"

I think you're asking about the difference between "[be] going to [verb]" and "[present continuous] + [future time]". Yes, both indicate a future event. Just ask yourself this simple question: "Can I change my plans?" YES: use "[be] going to [verb]" NO (or, it's very difficult): use "[present continuous] + [future time]"

Present continuous: She is playing piano (right now). Action happens at the current moment... **for example, I am answering your question. (right now....in this moment...) You are reading my answer...... at this moment. Going to: shows intention. For example, I am going to answer your question as fully as I can. I (am №1) (going to №2) (answer №3) your question as fully as I can. 1) am - it is a form of verb "to be" in Present as you know: I - am he/she/it - is you/we/they -are 2) going to - it is "constant" and shows intention. 3) answer - it is a verb Also, you can use /going to/ in Past: I was going to do my home task. (But I didn't because I caught a cold). * I am just a student, I am not a wizard..:))