1. "May dalawa akong kapatid." (This is the most general way to say it)
* May - have
* dalawa - two
* akong - my (possessive pronoun)
* kapatid - sibling
2. "May dalawa akong kapatid, isang lalaki at isang babae." (This specifies that you have one brother and one sister)
* May dalawa akong kapatid - I have two siblings
* isang lalaki - one male
* isang babae - one female
You can also specify the genders using the words kuya (older brother), ate (older sister), bunso (younger sibling), etc.
Here are some other ways to say "I have two siblings" in Filipino:
* May dalawa akong kapatid na babae. (I have two sisters)
* May dalawa akong kapatid na lalaki. (I have two brothers)
* Ako ay may dalawang kapatid. (I have two siblings)
The best way to say it depends on the context and who you are speaking to.