There are no direct trains or flights from Suzhou to Nanning. And no airport is available in Suzhou. By train, you could transfer at Hangzhou or Shanghai. Or, you could take train to Shanghai first and then take a flight to Nanning. For the flight info. in details, you could check Shanghai Flights(https://www.travelchinaguide.com/china-flights/cheap-shanghai-flights.htm) .