Just bought every thing, should I install the parts and do backup or before installing the parts?

Guys,
I see good help here, just bought an avalanche 07. Immediatly I bought the following:
1. Volant Cool Air Intake
2. Corsa touring 2 side exhust system.
3. SuperMaxx headers
4. Thermostats.

And finally ofcourse the Predator programmer. As new to all of this, any advice on the settings after ...

Thanks

Guys,
In our part of the world we use 93 or 98 Octane, is that will effect the mod if the settings for 93