Even though the official language of the country is Pilipino (Filipino) the reality is most of it is Tagalog, the native dialect from the Manila region. The claim is that since that is the largest single group of speakers and it is the nation’s capital, that is the most widely spoken language. The reality is there are as many speakers of Visayan as there are of Tagalog, and these are native speakers. Many of the millions living in Manila come from other provinces and have other dialects as their native tongue, or L1 (Language 1). For centuries Cebu City was the main city in the islands but that was changed late in the Spanish occupation period (1564-1898).
Whatever the reality of how many speak which dialect, the national language is over 90% Tagalog and 90% or more of all television, movies and songs are in Tagalog. If you plan to live deep in the province somewhere else then learn that local language but you won’t be able to follow much on TV. Additionally, everybody speaks some Tagalog/Filipino so if you can only learn one language, there is a good argument for making it Tagalog and not Bicolano, Cebuano, Illongo, Pampanga, Waray-Waray and any one of a couple of dozen other dialects.