Dont own a GM but I can give you an example of what I did when my Ford was new. 1st change was @ 3k, 2nd was @ 5k and future oil changes will be all @ 5k with a full synthetic. Air and cabin filter @ 20k. Spark plugs are planned @ 75k. Because of COVID I work from home and have been told it "may be" for the rest of my employment. My OCI could possibly turn in to once a year.
Driving style I would probably say is severe since its city driving, if not city driving its towing something, either a boat or a trailer full of off road vehicles, gear and 6 people, dusty or muddy roads and my driveway / easement and other friends and family also live on dirt roads. Ford recommends 5w20, Im in Florida so I have chosen 5w30 and have in my other Fords for the last 25 years. Hope this helps.