First start up tune
Find a tune for a 5.3 from the same year and use that as the base. Change the injector information to the correct values (as given by the vendor), increase the idle rpm, increase the running airflow (if it's a gen IV engine with dbw throttle) and it should idle and run just enough to get it to a tuner.
Don't get into boost and you will be fine. Monitor AFR and trims to make sure it's not going dangerously lean but it shouldn't unless the cam is humongous.
Might as well just get your car towed to the tuner and go from there.

