Wise or an E-Wallet (I use Touch & Go).. The wallets are convenient if you plan to visit nearby countries like Malaysia as you just change location and it converts your money- no fee, then change back when you get back..
Not to worry, you need nothing until May 1st after which it is a simple on line ENTRY QUESTIONER.. it is just a check for immigration. If you are worried just go through the E gate after you fill in on line and have entered once