The problem is not state socialism, it's the authoritarian side of it. Tankies promote authoritarian views similar to fascists but with a different economics view (not even that different some times), hence they prefer the dictatorships like USSR (in these days even Putin, which is idiotic), North Korea, China; over what they perceive as imperialist, the USA (I agree on calling it imperialistic and disliking it, but not on considering it worse than dictatorships).

I'm a communist which likes state socialism, but what is and was present in those dictatorship (ignoring the authoritarian side which I despise) is state capitalism.

The confusion comes from so much mass media that equates socialism with communism. They're orthogonal concepts! Saying socialism is the same as communism is like saying beer-making is exactly the same as cheese-making. Anyone who understands what beer and cheese are would be like, "I'm sorry, what‽"

The best way to think of socialism is that's it's a governance strategy that can be used wherever you want. Want everyone to pay taxes in order to fund and deliver government-run firefighting services? That's socialism. Want to do the same with the military? Socialism. Whenever the government is delivering some good or service by way of taxpayer dollars that's socialism.

Capitalism and communism are economic systems. You can have socialist government constructs under either capitalism or communism. It's just that communism doesn't really have the flexibility to provide goods or services in any other way than via the government.

Then there's countries like China that claim to be communist (and the Right loves to call them that) but really, they're more capitalist than communist. What they do have that most communists and fascist governments have is authoritarianism.

That authoritarianism is what fascists and "tankies" have in common: Fascists support an authoritarian, pseudo-capitalist government while "tankies" support an authoritarian, pseudo-communist government.

people who support Russia/Stalin/China regimes.

Congratulations: That, and only that, is a tankie. It is a good practical defintion for the term.

Are tankies people who are economically left but socially and politically right

As I see it, tankies are just the same as the Trumpers. You can't really say where they stand socially and politically, because they do not have a coherent opinion or ideology. Everyone who opposes their favorite regime is WRONG, and everything their favorite regime does is RIGHT. Bonus points for every action and opinion that hurts "woke lefties", because the favorite regimes of tankies are all inevitably incompatible with progressive ideas and ideologies.

without knowing anything about the corrupt oligarchies in Russia or CCP China?

Imagine the answer a Trumper would give when you ask them if they don't know about Trump's corruption and character. The tankies answer just the same in response to allegations in regard to corruption and character of their favorite regimes:

First of all, none of that is true, because the woke lefties, the media, and everyone are all corrupt, and lying. And what is true, is all a well played move of brilliant 5D chess which will save us all, because the supposed "corruption" is actually all part of a very smart and deliberate system of ploys and strategems which the woke lefties just don't understand.

Now, do the tankies and Trumpers truly believe that? Who knows. Doesn't really matter anyway. What is clear is that both of those "ideologies" are dumb idiots.