What's up Pinoy, Thai American checking in. I've been going back and spending time in Thailand once every 3 years since I was in elementary school, so feel free to ask me whatever you need. It's difficult to sum up my entire culture in one post, so I'll just breeze through with what I've enjoyed most.
In terms of location, I would breakdown the country into three sections- the North (Chiang Mai) has the mountains, Central (Bangkok) is the city, and the South (Puket and Krabi) has the islands. Personally, I would skip Bangkok entirely. Unless you're Buddhist and want to check out the temples, or are into tourist traps, it's just another Southeast Asian city. And right now they're doing the highway/train construction which is causing crazy pollution EVERYWHERE for the next year or two. So that leaves the mountains and the islands. Do both? Fly from each. Chiang Mai isn't that big, give it 5 days to a week. The islands also deserve about a week, maybe take it slow and stay a little longer. Puket gets a bad rap for being a tourist trap and sex spot, but that really only happens on major street where foreigners come to play. Just like Amsterdam or Vegas. Puket and Krabi are in the same region, but is separated by a large body of water. If you're staying in Puket, stay at Kata Beach. Otherwise, I actually recommend Krabi. It's cleaner, less Tourist Bros, and still has everything. While down South for the islands, book an island hoping tour. You do this by simply hunting down one of the many a tourist kiosk on the street and they'll show you what each tour offers. Book a 2 day tour- one that takes you island hopping, and another that takes you Kayaking through caves in Phang Nga Bay (pronounced Pung Nga Bay). They're gonna give you an asking price of about 2,000 Baht (only $60 USD), but like anything else you're buying in Thailand, you can haggled it down. Ask for 1,500 Baht. Each tour takes up a full day, and you get to chill at a lot of different islands.
How long are you planning to stay? This will dictate the amount of money you need. For two weeks, I would say $1,000-1,2000 for everything including food, hotels, and a flight across country is enough. You'll probably have a couple hundred left over, but that's better than being short.
In terms of food, a lot of my Filipino friends can't eat spicy. So you that's up to you. And really, just youtube "favorite thai foods" or whatever and write down the ones that look good to you. But if you have questions I'm here.