All welders are different. I don't think you can expect an exact answer. All the wire feeds I've been exposed to have a "suggested start settings" table for different materials and wire selections. Look for it in your manual.
For sure, I'd weld for practice to get used to your new box. You can't beat welding two pieces together and then trying to detroy them by beating on the parts in a vice. Most common problem with wire feed is a real pretty weld with no penetration.