I'm full of ambition / I'm raring to go / I can't wait to get started
I can't wait to eat / I have a huge appetite / I could eat a horse!
「満々」は文脈によって違う英語になります。例えば、
「やる気満々」= I'm full of ambition / I'm raring to go / I can't wait to get started
※full of = ~でいっぱい, can't wait to get started = 始めるのを待てない
「食べる気満々」= I can't wait to eat / I have a huge appetite / I could eat a horse!
※ huge appetite = 食欲はすごい,
I could eat a horse = 「馬を食べれるほど食欲がある」(イディオム!)