Interested in Language
Is it right to say 'I ate stomach full.'?
If not, what are the other ways to say it?
No, it isn't. Do you mean that you ate until you felt full? If so, you can say I ate until I was full. If you want to suggest that you ate too much, you can say I ate till I couldn't eat any more/another bite.
Till and until are synonyms. You can use whichever you prefer.
I am not a teacher.