Hi kristina, and welcome to cruise-chat.com.
I am very familiar with Norwegian Majesty, having cruised on the ship four times. I have both good news and bad news for you regarding Cabin 926.
First, the good news. Your cabin is one of the larger ones on the ship. While it's just 145 square feet (and will be a shock after sailing Disney), it's laid out pretty well -- and larger than the standard cabins, which are 108 square feet. I like Norway Deck. We stayed on this deck last year and found it quiet. It's also conveniently located to the pools and buffet, both of which are one deck above. We rarely had to take an elevator anywhere. 926 is in a good spot on the deck -- right in the middle, where the motion feels most smooth.
Now for the not-so-good news. This is indeed an obstructed view cabin. The lifeboat obstruction is about 90%, according to NCL. As you said you weren't quite sure if 926 is yours, I suggest that you double-check.
As for better cabins...it's not so easy on this ship. 926 is category EE, all of which have some obstruction, and some of which are even 100%. Moving up to a category D would put you on the lowest passenger deck, a far less convenient location.
Happy to answer any follow-up questions.