The Arrival is a bit overused. Many kids doing their HSC use it. Just because Peter Skrzynecki's poetry is about immigrants, doesn't mean you related text must be about it.
i have about 2 weeks to do an english speech on how the concept of belonging is explored in 2 related texts and romulus, my father.
and the 3 texts need to be interlinked...
what related texts should i do if i only have a limited time to read/watch/analyse?
and how do i link texts to each other? aren't they all linked anyway if they all explore belonging?
Yes, they are all linked if they explore belonging - which makes your job a whole lot easier.
I suggest you have a look at this thread for ideas on what related texts to do.