Accepting and then rejecting an offer

Hi reddit. I am not totally sure which flare to use here, so I hope I used a fitting enough one.

I am a university student and I have been handing out resumes for the past few months for summer jobs not relating to my field, mostly park maintenance or city maintenance.

This Wednesday I had two interviews with two provincial parks. The first one went well, and the second one went well on my end, but the hiring people were very weird. They said something along the lines of "Are you handing out other resumes right now? Because we wouldn't want to go through this whole process if... well, you know." This totally threw me off. I feel like it's obvious that I would be handing out other resumes? And the implication that I should be sure about a job before even getting an offer? I don't know, is that normal? There were a couple other things during the interview that felt weird, like them asking the same questions worded differently several times, making fun of the provincial park I had worked at the previous year for being ugly, etc. The interview also took FOREVER, I have never in my life had an interview last for an entire hour. Maybe that's normal for a "career" type of job, but it seems weird for a term/temporary student position.

Anyways, today (Friday, two days later) they have reached out offering me the job. In my previous experience, I usually interview in late February/early March and don't get an offer until late April, so it's already very weird to me that they have decided so quickly. After the strange interview, and the fact that it's far from home (therefore more expensive), I am not interested in this job really at ALL, however if it is the only offer I get I do desperately need money for school and would definitely need it.

Is it normal to accept an offer and then turn it down later for a different one? Is it rude? Will this get me like... blacklisted from provincial government work? I have never not accepted the first offer I've gotten, and I have never rescinded my acceptance before.