Tow/Haul button or dash light? & front light question

What is your question?

I just bought this truck last week. They said they didnt know if the tow haul was working,but thought the light was just blown. I haul horses in the mountains, so I need to know. I'm scared to mess with it a lot since if I leave it in tow haul I could burn up the transmission. How do I tell if my tow haul button is broken or if it's just a blown dash light? Also both front lights beside the blinkers are blown, are those the daytime running lights, that's the only thing I can figure?