Like English there is no gender assigned to common nouns, including those of Spanish origin. The only exception is Spanish-origin words refering to a type of person or occupation. But even here, the article (ang, ng, etc.) is gender neutral. Example: Ang abogado/a The lawyer or attorney (m/f). Ironically, Tagalog-origin words can even be more gender neutral than English. Example: kapatid brother or sister.
For plurals, add mga immediately before the noun. Example: Mga hayop Animals. Adding "_s" does not make anything plural, and is sometimes used on Spanish nouns regardless of whether the topic is plural or not.
One point of confusion is the word Filipinas. It can mean either The Philippines (the country) or a group of Philippine females.