OK I know you're new and all but really, if you can't figure this out then goo luck actually programming your 250. You've got a LOT of research to do.So, as for your radio:
Main screen: select model type and switch to airplane (doesn't make sense but that's how it is).
As for the parameters shown, forget it. Set travel for all channels to 100%, subtrim to 0. You'll do most of your fine tuning in the software.