[2022] Need some advice...

In order to purchase new ships you need:

XP


Credits

XP (Experience) is used to "Research" new parts of the ship, or research the next ship in the line. Higher tier ships tend to be more powerful then the current ship you are playing.

Credits are the money you use to buy something you've researched. You might buy a new Hull or Gun. You could buy a new ship.

She is an older Premium Ship that recently returned for a limited time but is not currently available to acquire.