I'm now in 7th grade and am considering buying an iPad (with keyboard). Now it has hit my head that I may need a laptop for school in the next few years. Is an iPad with a keyboard enough or do I have to buy a laptop?
That doesn't make a big difference. It is only important that you have a real keyboard instead of a touchpad on which you can work and write quickly.
there are other decent tablets, not just the most expensive ones
Many prefer an iPad because you can write on it with an Apple Pencil. With a laptop you just type. This makes drawings much easier for you
The question is what you should do with it. If you should install special software, a laptop might be better.
Why don't you ask the teachers or students from a higher class?
I would recommend a laptop with Windows 10. This has the advantage that you have a much larger selection of software. For example here: https://www.otto.de/...=978300090