What is needed to go abroad??

I've never been abroad.

But I may be going to go abroad in this summer to attend scientific society,
and in future I want to study abroad.

At this point, I want you all to tell me what is needed for it.

For example,
I've just known that without a power transformer
I'll be in trouble to use some home electric applications.

In your experiment, what is needed??
If possible, please tell me that.

Thanks for reading my entry!!