Salaam, Nasim. Hale shoma che-tor-i :o)
This sounds to me like it was written by someone from "the valley" area of California, or that the author is mimicking that American way of speaking.
They like, tend to like, say like, WAY too much, and like, it sounds a little, like ditzy.
"too" here means something like "too much"; "a quantity that annoys a person", or "a quantity or level that one finds unpleasant. "
I ate too much food on Christmas, and now I feel sick.
I spent too much time at the gym, and now I'm sore.
I can't afford that new car, it's too expensive for me.
I don't like war movies, they're too violent for me.
I don't read the newspapers, they're too depressing.
In your text:
It's too much for me = everything is pastel. Every color, every building, even the plants, and the roads and the clothes that people wear, it's nothing but pastel and that is more pastel than I like.
too like the beach houses in LA = there is absolutely no difference between the houses on the island and the beach houses (or it seems to me that there's no difference). They're too similar, too like, too alike. Same design, same details, same colors, same everything. And because they're very similar (very alike) I don't like them.
Tacky is hard to describe. Tacky is an emotion you get from a certain type of decor. If I thought of tacky decor for the beach, it would be surfboards, and blankets and shark teeth, and volleyball, and sandles, and bikinis, and all of that imagery. It's designed to almost advertise "the beach", and it's not authentic. So "too tacky" is like too inauthentic. That is to say, 99% for show only.
Hope that helps!