Humidity is all a preference thing. You will hear of people incubating from 1-17 days anywhere from 15%-50% humidity. I personally go for 25%-35%, have had my best hatches there for days 1 -17. Then I up it to 55-60 for hatching and have never had a shrink wrapped chick. Some people will tell you this is way to low for humidity but it all depends on what works where you live and what works for you. Try to find people locally who incubate and see what they do for their humidity range and try to base it from there, that is generally a good starting point.
I second waiting to add the water to your incubator till you get the temp figured out because that is going to make it take longer to stabilize temperature in the incubator.
Turn down the temp control, open the door and let it cool off inside for a few then let it stabilize back and keep doing it till you get 99.5 to 100 for a solid temperature. When you add the water this will mess with the temp sometimes but do not do anything, the incubator will fix itself. Same thing when you add eggs for the first time, it will drop the temp in the incubator sometimes, but temp will come back up in several hours. The eggs need to warm to the incubator temp slowly and that is what causes the temp drop in the bator.