child support for single parents

I'm 28yrs old and have a son who just turned 3 this year. I do made to order cakes as my source of income. But i'm all stressed out thinking of my son's financial needs in the future. He's now into schooling (toddlers). The father of my son did not and have never given him support ever since i gave birth. He doesn't have work, but he lives in a subdivision in cavite (his parents are renting the big house for him), he's into breeding imported dogs as his business, he does have a car but its not named after him. Now, im trying to communicate with him with regards to his support to our son. He's always like "wala ako ngaun" and i will tell him, "what if wala na rin ako.. pano ung bata?" I'm so pissed because i always see his posts on facebook that he goes to this places, try food to this restaurants, buy something to his car, but yet he has nothing to give to his son. He depends on my parents, that they're able naman daw. By the way, he acknowledged my son.. my son uses his surname.

-Is it ok if i file for child support?
-How will start the filing?
-How much will it cost me, like the atty's fee and all?


Actually we've talked about me, filing for child support but he told me "wala ka mapapala" because he doesnt have work and doesnt have any assets.. thats what he's always pointing at. suportado lng sya ng parents nya but he lives luxuriously. Surely will appreciate for the answers.. thanks so much.