Welcome to the site!
Would like to start by saying great job on the upgrade to a 55Gal, because it is bigger than a 30Gal, however, we do recommend at least a 75Gal tank for 2 Oscars together, while a 90Gal is "Preferred" for two of them. Also, just an FYI incase you haven't been told yet, it is best to soak any freeze dried foods in tank water prior to feeding. This allows the dried foods to soak up the water and expands, if it is not done before feeding them to your fish, then the freeze dried foods will expand in your Os tummy and can be the cause of a number of issues.
We have tons of great information around here and very knowledgeable members, so browse around, make yourself at home and enjoy it! And by all means any question you have, feel free to throw it our way!