Since the folks that you just handed $300 to do very little work would not or could not look up when your bike needs it's next service, I'll do it for free. It took me all of five minutes to pull out my manual and find the information and a little more time to type it out. I guess that maybe, if you had dropped another $200-$300 they could have figured out when the CTX700 needs its next service.
Everything is in your owner's manual. I would tab this entire section p-51 through p-98. It's got all the information you need. You can decide for yourself how much you want to let the service folks do and how much you want to handle yourself, but I think that once a rider understands where and what he or she is checking, that he or she should be able to handle everything between the 8,000 mile services at a minimum. Like I stated in a post above, it may be helpful for someone to show you some of the monthly checks and some of the items at the 4,000 mile check the first time around, but after that, I wouldn't take a perfectly good CTX700 in but every 8K.
Pre-ride inspection to be done before each ride p.53
Periodic checks p.54, which includes drive chain to be performed at least once per month.
With regards to the drive chain, 500 miles or as needed, whichever comes first. As needed means any time the chain gets dry, dirty or develops slack even if it's not been 500 since the last check. Chain drive service is listed on pages 60-62 and 88-90. I'd get in the habit of checking the condition of the chain and sprocket some time during each ride; either before or after. I prefer after, since you have a warm chain to do service if necessary.
At 4,000 miles shown on odometer
Crankcase Breather Check - Check more frequently if often ridden in the rain or if
ridden often at full throttle.
Check engine idle speed - All this means is that the engine is supposed to idle @ 1200
RPM + or - 100. Just look at the gauge and make sure it's idling where it is supposed
to be. Reference page 142.
Check brake pads; brake fluid level; and brake lock. How to perform these checks
is explained in the owner's manual.
At 8,000 miles, you've got some of the same checks plus some more inspection items, plus the next engine oil and filter change, plus valve clearance check. I'll take mine in for the 8,000 mile check, because I have no confidence with valve clearance, but I may one day start doing that check and adjustment on my own too.