If you need to file for a divorce or legal separation, you need to first be a resident of Arkansas 60 or more days before you can file the action in Arkansas. Your intent to reside controls whether you are a resident of the state. Then you will have to file the case with the clerk of the court in the county where you reside.
If there are children from the marriage and/or land and other property, ;you should seek the advice of an attorney. Visitation, child support, and custody can be complicated. Without an attorney, you may not have your rights protected. A divorce in Arkansas can be final within 30 days of being filed if all goes well.
If you have any questions, please let me know.