My pay is at 1.8k/month which I do not expect to increase in the near future. And I have plans to study uni part time next year and it is quite near to my workplace. Should I stay or resign?

That work environment sounds like every other office. It’s nothing to worry about. Since you’re intending to do a part-time degree, I think the most important aspect of your job is whether the people embrace such an idea. Is your boss ok that you may need some time off to study? Are your co-workers ok to cover your duties when you’re not at work? If yes, then staying is a good option. As for the job prospect, maybe wait till you’re done with the degree then see how again.

You've got 2 choices: stay, or find a new job. Staying gives you status quo; easier to manage the upcoming additional school work.

If you want to find a new job, make sure it give you the time to study too. Every work place will have its fair share of toxic people. You have to settle in your job comfortably first beforing going for your studies.