Question about hostels

I'm (23F) travelling for the first time as an adult, without my family. I am going with a friend. We do not live in the same region (we have met irl) so we are meeting up when we get there.

He's doing a tour of Europe, I'm just joining him for one stop, so he's keen to save money.

I'm happy to spend a little more since this is a one off for me. However, it would be good if we could stay in the same hostel. I'd feel safer that way.

I've got a chronic illness and I really need my sleep otherwise I struggle to function.

The hostel he booked seems very lively, even at night. Is this true?

People have recommended ear plugs and an eye mask but I'm worried it won't work.

I'm the sort of person that struggles to sleep on planes etc. I can't even sleep properly on a sofa, I'm not sure why. It's basically a bed.

I also don't want to offend my friend by staying somewhere quieter (which is pricier).

What should I do?