Welcome to the forum
It would be helpful if you put your country, province or state, and area in your profile. It does make a difference
Cage or items for in the cage?
If you are getting 2 to 3 ratties buy a one or 2 section critter nation cage, otherwise a 2 section critter nation cage (see amazon.ca) ............ A huge cage that is at least 4 cubic feet in size (with at least an additional 2 cubic feet for each rat more then 2 rats) and a base that is at least 30 inches by 18 inches with height for large levels (not thin shelves). But more horizontal space and a larger cage is better.
Small bar spacing is important to keep rats confined for their safety, and also to keep other animals -out …. such as mice or predators that can get into homes (such as the ermine).
Items: a food dish, at least 2 sources of water, one of which needs to be a water dish that cannot be upset, a house, large corner litter boxes, fleece hammocks, a space pod, a solid wheel at least 12 inches in diameter, tubes hung on the side of the cage, tubes in the cage, solid floors, bedding (hardwood shavings, unscented paper based shavings, fleece, etc, boxes etc
For information on cage, diet, toys, health care etc see the Reference Thread
https://www.ratshackforum.com/threads/reference-thread-read-only.35894/
Here is some basic information:
https://www.ratshackforum.com/threads/thinking-of-getting-a-rat-things-to-consider.32306/
More info regarding what you are looking for re tips on travel would be helpful
