As Joe and Tim have said, 'greedy' is wrong: it suggests something selfish and excessive. In addition to Joe's suggestions, I'd add one more: "I am keen to learn more English". This is a common expression in British English: it is also understood but not often used by AmE speakers. For me, it seems to be closest to the idea that you want to express.

thanks Tim and Joe🌹

I agree with Joe and eager is probably closest to what you seem to want to say.

I don't think it sounds 'natural'. Greedy - is a selfish desire. Example 1: "My sister will not share her snacks because she is greedy" Example 2: "There is no need to be greedy, there is plenty for everyone" I would reword the sentence to say: "I am (ADJECTIVE) to learn more English" I am 'anxious' to learn more English I am 'excited' to learn more English I am 'eager' to learn more English