I hooked up a battery backward

This is a RV; 2003 Winnebago Itasca 29B. It is a E450 Super Heavy Duty chassis with a 6.8 liter V-10. I hooked the battery up backward and smoke came out of engine. In my brilliance I tried to start the engine as well. Now the alternator doesn’t charge and the ignition does not start the engine. I had a mechanic put in a manual start that requires the ignition turned on and a screw driver. I live in the RV so I can’t take it to the shop.

There are RV shops that will service your rig while you’re in them. rvforum.net should be able to point you to one near where you are.

Sounds like you blew a few things and will need to have them replaced.