If you plan on doing your own maintenance, I'd get hold of the service manual. It's a great resource with step-by-step instructions and the complete maintenance table. I don't know that I do things in a certain order.
For the first maintenance, I'd simply assume that none was ever done, i. e. do all services specified and inspect/clean/change everything.
When my DL650 was new, I tried a lot to optimize things ("do this while you do this"). But eventually, I got in the habit of simply taking off the fairing every 3,750 miles (the standard maintenance interval). You think it's a hassle, but after a while you'll do it in minutes, and it facilitates access to so many things that I never even start working on the bike while the fairing is on.
If you stick to the service manual and change/clean your air filter every 3,750 miles, you'll have to do that anyway.
For the first maintenance, I'd simply assume that none was ever done, i. e. do all services specified and inspect/clean/change everything.
When my DL650 was new, I tried a lot to optimize things ("do this while you do this"). But eventually, I got in the habit of simply taking off the fairing every 3,750 miles (the standard maintenance interval). You think it's a hassle, but after a while you'll do it in minutes, and it facilitates access to so many things that I never even start working on the bike while the fairing is on.
If you stick to the service manual and change/clean your air filter every 3,750 miles, you'll have to do that anyway.