Before you go on vacation abroad, make an appointment with your doctor or pediatrician to get an update on your baby's vaccines. In some countries, certain complementary vaccines may be useful. Find out as soon as possible, because some vaccines have a fairly long immunization time. Don't forget, of course, to take your baby's health record with you. Take advantage of this doctor's appointment to take stock of the various medications that may be useful to you on site:antidiarrheal, rehydration solution...
If you go to a country at risk of tourista, be careful. If your baby is exclusively breastfed, no worries, continue to breastfeed normally. If this is not the case, or for older children, provide sterilizable bottles and airtight storage jars. The electric sterilizer or sterilization tablets can be very useful. Be sure to only give your baby bottled water, and remember to wash and cook fruits and vegetables well.
If you go on holiday by plane, the trip can be difficult for a baby. Remember to make him drink regularly to avoid ear problems. Do not forget to inform the airline that you are traveling with a baby to benefit from the appropriate equipment (nacelle, games, meals, etc.). As for jet lag, deal with it gradually, letting him take naps when he's tired and trying to shift your baby an hour or two a day. It all depends on your destination!