You're arriving about 4pm ..... not sure if this is in Belize City or Ambergris Caye.....If it's BC, dont' expect the flights to AC to necessarily be on time - but they'll wait for you if the plane's not full, so let a baggage handler know that you want Tropic (or Maya) Air and then follow your bags. Time, you'll soon find out, is rather elastic in Central America. You'll have plenty of time. After you arrive at AC airport, take a taxi to wherever you're staying (you could ask the driver to stop at a store along the way where you could pick up a few things - they seem to stay open till about 9pm), check in and then find a place for dinner. If you're south of the cut, stroll into town. If you're north of the cut, your choices are more limited, but ask at your hotel. Take it easy. It will all be fine. Have a wonderful time!