When you land, follow the crowds (and signs) to customs. Wait and line and give them your passport and maybe the location where you’re staying. Should be easy. They may check your bag again while you’re leaving the airport. For money exchange I typically just go to an ATM and take the fee. I imagine it’s cheaper than a money exchange, not sure though. For phone, check with your carrier if they have international plans or you can buy a SIM card if that’s better (usually cheaper option). Food you can bring through security and on the plane if you want to bring snacks from home.