In the Eastern United States, commonly used cruise departure cities are Miami, New York and Baltimore. Other possible cities are Norfolk and Boston. San Juan is another popular site.
Galveston island has a great port you could leave out of to go onto your cruise, it has a great beachfront and many resturants. It also has many girt shops.
Miami, FL is a cruise departure city and the majority of the cruises leave there for the Caribbean. Boston, MA has cruise ships departing for Bermuda which is pretty close due to its location in the Atlantic. Los Angeles, CA is another departure city to the western coast of Mexico.
It depends on your cruise destination. Cruises to the Caribbean and Bahamas often depart from Port Canaveral, Miami, or San Juan, Puerto Rico. Cruises from Baltimore, Newark, and Philadelphia depart for Bermuda and Eastern Caribbean destinations. Cruises to Mexico and the Mexican Riviera commonly depart from Galveston and Los Angeles.
Your choices in the east: Baltimore, Boston, New York, Charleston, Ft. Lauderdale, Jacksonville, Miami, Mobile, New Orleans, Norfolk, Palm Beach, Philadelphia, Port Canaveral, Tampa, Washington D. C. Texas: Galveston. West: Los Angeles, Portland, San Diego, San Francisco, Seattle. Alaska: Anchorage, Fairbanks, Juneau, Seward, Whittier. Hawaii: Oahu.
There are several ports of call along the US coastlines. Galveston Texas has always been my favorite, since it is the closest and a short trip to the Caribbean.