I am wondering if in my first day, it is good to wear tie and suit (or
just suit) or something less formal.
I don't know any Developers who wear ties and/or suits at work these days. In my area, the norms seem to run from anything goes (shorts, flip-flops, etc), to business casual (shoes, khakis and a shirt with buttons and a collar).
But it would depend on the culture in your locale and at your workplace. It's possible (although unlikely) that formal dress is the norm at your new shop.
If you interviewed on-site, you could have looked around and see how others were dressed - that would be a clue. Similarly, how the folks that interviewed you were dressed is a clue.
But if you still aren't sure, you could do what I did when I was young and unsure. Call the office. Talk to the receptionist, HR or office manager, and ask how other Developers are dressed. While it might feel awkward to ask that question, you are likely to get some friendly help, just as I did.