Hi fx, I think this question is on topic. Bear in mind that this is just my opinion and I'm not the EA police (:

You might want to check the Opportunities Board:

https://www.effectivealtruism.org/opportunities

At least in theory it contains stuff to do that is less commitment than a full time job opportunity.

Then, it depends if you are looking for a paid opportunity or you just want to contribute. If it's paid, the space is quite crowded and competitive.

If you want to gain experience, your best chances are probably outside of EA-themed organizations, just because it's a small pool.

If you want to do something impactful right now or do something to feel more part of the community, there are some ways to get involved: you could start a group in your university if there isn't one, or you can ask your local EA Chapter if they could use some support. Keep in mind that managing volunteers takes time and it is not always welcome, but sometimes it is worth it.

I would also consider applying for career advice.

And all this is with the important caveat that depending on what you're doing at university, focusing on what you're studying can be a smart path towards impact later in life.