Could you please identify the grammar point of 필요한거 아니면 연락하지마. I don't understand the grammar of 한거. Is it from 한거에요 ( 한거에요 use for past tense so, It does not make sense to me.)

How to use ~되거든 ? and what does it means ?

다른거들고가? what dose it means? Could you please help me to identify the meaning of each word and also the grammar of this sentence ?

How different between 돈을모아요 and 돈을저축해요 ?

how to use 찾아와서 ?

포문 을 연 What does it mean ?

해먹을건데요 what does it means ? Could you please help me to specify grammar rules of this sentence. I try to find it but i still don't get it