When you arrive to Bogota's airport you can take a taxi to "Terminal de transporte". In that place you can take a bus for differents destinations of Colombia in this case I will be concentrated in North of Cundinamarca,the price of the ticket depend of your destination for instance if you want go to Nemocon you should pay more or less $4000 Colombian pesos.
If you prefer you can take "El tren de la sabana" this can take it in "La estacion de la sabana". It can take you from Bogota to Nemocon this have differents stations where you can buy desserts and other kind of food. Inside the train you can listen Colombian music and know differents towns close to Bogota.
Other choice is to rent a car , in that case you should take "La autopista norte" to the Nort passing Chia which iss a twon very near to Bogota, next to Chia you will find Cajica