Hua Hin is the fuller resort town, with railway history, markets, restaurants and Khao Takiab. Cha-am lies north in Phetchaburi province and offers a different, generally quieter beach base.
The railway station, central beach and night-market area make Hua Hin workable without a car. Khao Takiab is south of the centre and adds temples, views and another beach area, but it needs a local ride.
The beach changes with tide and weather, and different sections have different levels of activity. Choose accommodation by neighbourhood rather than assuming every Hua Hin address is an easy walk to the centre.
Cha-am is north of Hua Hin, while Pala-U Waterfall lies far inland toward the Myanmar border within the Kaeng Krachan landscape. They should not be bundled into one casual half-day.
Use Cha-am for a quieter coastal stay or stop. Give Pala-U a dedicated road plan, current park information and footwear suitable for wet ground. Families may get more from one beach base than changing hotels between two nearby towns.