N'Djamena International Airport (IATA: NDJ) has limited but functional international connections. Ethiopian Airlines, Air France, Turkish Airlines, and a few African carriers serve the city. Ethiopian Airlines via Addis Ababa is often the most practical routing from outside the continent, and from there connections to most African cities are possible. Flights fill up and cancellations are not unheard of; build some flexibility into your schedule.
The main land border crossing is with Cameroon at Kousseri, a short pirogue ride or road crossing from N'Djamena. This border is generally open and used by locals and travellers. Other overland crossings into Sudan, Niger, and the Central African Republic are either difficult or dangerous depending on the current security situation and should not be attempted without current local knowledge. Check conditions carefully before attempting any overland approach other than the Cameroon crossing.