Complex sentence: The travel journey lasts three days and it is very interesting although you must be very careful when the sun goes down with mosquitos; an advice: to wear shirts with long sleeves and long trousers.
Split into simpler sentences: The travel journey lasts three days and it is very interesting although travellers must be very careful about mosquitos when the sun goes down. Travellers are advised to wear shirts with long sleeves and long trousers.