How can I file for divorce in Johnston County NC without a lawyer?

I don't know, but my ex wife did it pretty effectively WITH a lawyer (and I ain't set foot on Carolina soil since!!).
Filing your own papers is easy but you might want to look a few already filed at the courthouse. Talk to the clerk of court about seeing some examples filed and they can provide you with the proper papers. I know a woman that did this with the clerks help and she did an adoption without a lawyer. Just make sure you get all the wording right.
you may also want to get more information for filing your divorce. I have attached a very good site that you can pull tons of information on regarding filing a divorce. Good luck
go down to your local county court house, go to the clerks office, they will have the paper work for you to file for divorce pro-se

All those previous answers were good. My state has one more choice that might be available to you, also. My state bar has a pro se divorce clinic that meets weekly to help people with paperwork. Call your state bar office and check on that, too. The suggestion of going to the court and looking at someone else's divorce file is also very good. I would not recommend a completely pro se divorce if you have children. There is a middle way. You can hire an attorney just to write the papers for a small fee. Attorneys can limit their participation in a case in my state.