Technically yes, but we commonly refer to members of the House as congressmen/women and members of the Senate as senators. Being a senator gives you more power because there are only 100 of them compared to 435 House members, so it is a meaningful distinction to make.
https://en.m.wikipedia.org/wiki/First_lady https://en.m.wikipedia.org/wiki/Second_lady
Many do, though the title is perhaps not used as often in most as it is in USA
What? The term “second lady” most certainly existed long before this.
Orwell was a leftist who wrote from a leftist perspective. 1984 is about Stalinism specifically and totalitarianism generally. It is not about communism, unless your definition of “communism” only includes the Soviet variety.
In case you’re serious
https://en.m.wikipedia.org/wiki/Charon