I think basically your text in Japanese is OK.
My name is Jerwin and I was born on October 12, 1989. I grew up in Porac, Pampanga.
Watashi no namae wa Jerwin Marcelo desu. watashi wa 1989nen 10gatsu 12nichi ni umare, Porac, Pampanga de sodateraremashita.
The way of stating date is correct.
The place name should be "
Pampanga no Porac de".
I live together with my parents and two siblings.
Ryoushin to futari no kyoudai to tomo ni sundeimasu.
"tomo ni" sounds very polite but it is OK.
You can replace it with "issho ni", which is a little more colloquial.
(I'm not sure about the situation where this self-introduction is to be made, so it is up to you.
)
I started going to school when I was 5 years old and by the time I was 12, I enrolled in highschool.
watashi wa 5sai no toki, gakkou e kayoihajimemashita. Soshite 12sai ni natta toki, koukou ni hairimashita.
This is also OK.
If you make it sound more formal, you can say "nyuugaku shimashita" instead of "hairimashita".
I am currently attending college to obtain my degree.
Ima wa boku no gakui wo eru tame ni daigaku ni zaigakuchuu desu.
Again, if you want to sound more friendly and less formal, you can say;
- "gakui wo toru tame ni" instead of "gakui wo eru tameni".
- "kayotte imasu" or "benkyou shite imasu" instead of "zaigakuchuu desu".
I eat anything and everything that tastes good, but I like seafood in particular.
Nandemo kademo oishii mono nara tabemasu ga, seafoods ga totemo suki desu.
Anything and everything is usually written "nandemo ka
ndemo".
To sound more natural, you can say "ohisii mononara nandemo tabemasu ga".
"totemo" simply means "very (much)".
If you like seasfood
in particular, "
tokuni shii-fuudo (seafood) ga sukidesu".
I don't have a favorite color, but I have an obsession with the color green.
Suki na iro wa toku ni nashi desu kedo, midori no iro ni kodawari ga arimasu.
"toku ni nashi desu kedo" sounds very informal compared with other part of your text.
To be coherent in style (formality), I'd say "toku ni arimasen ga".