Welcome! It’s only a mistake if you think of it as one. If you maintain the engine properly, change your fuel filter with your oil change, drive the truck on long trips(stop and go is terrible for these), and for the love of god look into a tune to allow for the egr to stop functioning, then the truck tends to live a happy life.
Tunes are available from a few places, sofaking tuned, hd diesel, and I think there’s two more that turn the egr off. If you have a computer it’s a fairly straight forward process.
As far as oil changes, 6-8k is as far as you want to go between changes. Fuel filters are 10-15k
I bought mine with 113k, tuned at 132k and have 150k on it now. Glow plugs are a pain if they fail but a good diesel mechanic can get you straight.