You can have one, but it's not necessary. Small case, I believe you can handle it. However if you fear something at the interview, hiring an attorney may help.
Believe or not, you will see it's very hard to find an attorney for this type of case. They will say you don't need. It's up to you if you really need.
You have to follow the interview notice to prepare all documents. If you feel confident, there is no problem to go by yourself.
For the case having arrest and court, it's better to prepare the following two type of documents: 1) open arrest records. you have to request it at locel police department. It takes two weeks to have it. They will send you a postcard to show it's ready for you to pick up. 2). Certified Court copy. You can visit your local court office and ask the front desk to print out all the documents they have in their computer system. if you got fine in that case, it's better to ask for a copy of payment.
You can bring any document you think it's good for you to explain what happened in that processing. Be sure to say the same thing as stated in the arrest open records. If your case was dismissed, it's good. You can bring all documents to show the progress and results.
Be sure to hand in the documents IO asks. You don't need give IO everything you prepared. You may ask IO to see what else he needs to grant your GC before you leave. Typically IO is nice. Their work is to collect all information they need. If you miss something you did not prepare and IO asks for it, don't panic. You can ask for permission to bring it back to the same IO later in the same shift at the same day.
Business dress, be polite, be confident, 10 minutes earlier than the scheduled. This is one of the processing, it's a small test.
I believe you can handle the interview. No jail time, no problem as I know. Be prepared.
Try to recall the happening and review the arrest open records one more time with your spouse to make sure you and your spouse can have the same thing to tell the IO if asked to describe the situation happended for that arrest.
Bring some family photos to demonstrate you have good relationship with your spouse even you have that conflict. You have a happy family. That arrest could be only one mistake you made in your life. You love your spouse very much,....
All in all, Just help you to prepare evidences to show you are not that bad man. You made mistake and you correct it.
It depends on the onsite interview. What I'm saying here is Only for your reference. Everything is up to you. Do your best.
Good luck,
