"I generally don't know about these things", all I can say is that it really shows.
You're not wrong that we can't glean the full picture from the snippets you've posted but the DT energy oozes out of everything you say. There's nothing wrong with that, of course, we all have to start somewhere but you're inviting the criticism when you come out swinging by calling this girl a possible gold digger over what, 3000-5000¥ spent between the two of you on sweets?
A lot more here I could lay into but I'll take your inexperience in stride and recommend you approach dating in Japan as you would anywhere else and set personal boundaries on what you're willing to do and how much you want to invest in terms of time and money then actually try to enjoy the process and get to know the person in front of you. If she just wants a free meal you'll find out soon enough and that's money you've already severed as "entertainment fees" which you'll know how to better allocate next time. Then you can come crying online, you'll have something of substance to say at that time and won't be crucified publicly.