The first trip will be your best trip because everything is new. But don't get so wrapped up in looking at the scenery (human and otherwise) that you stop being a defensive rider. You will encounter some extraordinarily good riders and some extraordinarily bad riders. A lot of riders are so busy watching everything that they aren't watching the traffic signals, people turning, changing lanes, etc.
Be ready for extreme changes in the weather, even on the same day. It can be clear and warm in the morning and raining/hailing in the afternoon. And that is just in Sturgis. Depending on your route, you can also run into temperatures over 100 degrees, monsoon rains, cold weather, etc.
Don't overpack. You can easily take too much which only serves to make your bike unstable. Think about shipping some of your unneeded stuff back before you head back home.
Don't overextend yourself on the miles ridden per day. It is easy to get caught up in the excitement of the ride and then ride to the point of exhaustion. Not a good idea to stop for the night and being so tired that you can't hold up the bike to put down the kickstand.
Have fun.