Overseas Before Enlist

I got my enlistment letter and I'm going in on July 10th, but I want to go on a long overseas trip lasting for 12 days.

I will be back for enlistment, but will they approve me?

dun even need their approval. just go as long not as long as 3 months can already.

but must go to ICA building to renew your passport if it has already expired rite?

can go. obviously you havent searched the forums i posted the same question a few monthes ago.