Tagalog is widely spoken and as with most parts of the Philippines, almost everyone can converse in English. However, you may hear some of the locals speak in a dialect called Ilocano.
From Manila, one can take a bus operated by Victory Liner. They have five terminals that are located in different cities - Caloocan, Cubao, Kamias, Pasay and Sampaloc. With the exception of the Kamias terminal, only the four others have trips to Olongapo and Iba.
The nearest from the three international airports in Manila is the Pasay Terminal located along EDSA, Pasay City. From there, it’s a 5 hour bus ride, depending on the traffic, to Iba, the capital of Zambales. Available buses are aircon and non-aircon. One way fare from the Pasay terminal is 346 pesos (according to Victory Liner website, subject to fare increase). The first trip leaves at 5:00am however, based from experience, the time of departure changes from time to time.
Another option is to hop on a bus to Olongapo from either Pasay, Cubao, Sampaloc or Caloocan, since the frequency of trips per day are more. Upon arrival at the terminal of Victory Liner Olongapo, you can transfer to one of the buses going to Iba or Sta. Cruz. Sta. Cruz is the last municipality that comes right before the province of Pangasinan where the famous Hundred Islands are located.
You can take a jeep to travel from one town to another. The standard rate is around 7 pesos per 4 kilometers. You can also take a tricycle if traveling within a barangay. Minimum fare is at 10 pesos per person.
In Iba Zambales, there are a ton of restaurants, serving everything you could want, including Jollibee, and McDonald's. Most of the better places to eat are close to the town center.
You can find pretty much any drink you would like. You should refrain from drinking the tap water. Bottled water is very plentiful and within the last few years there have been several restaurants built including McDonald's, and Jollibee.