The "600 cc Sport bike" and "New rider" really stick out. Nothing you can do about being new except practice. All 600cc bikes are not created equally either, so some of this is best guess for you.
Slow down for the road conditions. There are new things to watch for in the wet. Center of the lane has been talked about and despite some beliefs around here is a poor choice on dry conditions as well. Watch for "rainbow" effects. That is oil, fuel or something equally as slick. Watch out for the beginning of a rain event too, it will float all the oils and junk off the road. Asphalt age can make a lot of difference, and concrete, brick(stay off this if possible), gravel and everything else have different traction qualities. IMHO concret is best, but YMMV.
Speed is relative, I have put thousands of miles on the highway at full speed limits, but they were wide open with limited traffic. The main thing is DO NOT do anything fast. Take offs, braking, maneuvering. Plan farther ahead than normal and keep your game on high alert. This is one of the worst time in your life to get laxed.
Maintain your ride. Good rubber is a must on 2 wheels. All tires aren't created equal either, so do your homework when you buy. Knowing your brakes and how they react is a must. Well,,,,,,,, just take care of your ride no matter what.
Do you have ABS? I don't want to start the whole pro/con thing, and I am not much of a fan. Not because they aren't a good thing, but too many people think practice isn't needed to stay alive. ABS aren't made to stop you "faster" although they will in some conditions, they are made to keep you in control. SO, that said, practice hard braking wet and dry.
Gear. You gotta be comfortable and warm. Wet will chill you to a dangerous level in a hurry on a motorcycle. I ride a tour bike and usually have no problems and really don't get that wet, but I also have good rain gear with me 365 days a year. Your choice and you have to decide what works for you.
Good luck, Don't fear the rain. Stay off the throttle hard. Stay off the brakes hard. BTW, no finger pointing, but,just because you don't think it is too agressive doesn't mean it isn't. Food for thought.
Smooth, alert and well maintained will get you far in your motorcycle life.