What is the conditional?
"The conditional" is just a fancy way to say that we are talking about "would" phrases -- anything that would happen or could have happened or would have happened.
How do we form the conditional?
We use the word skulle much like we use the word "would" in English. All you have to do is add skulle before the verb infinitive! Easy peasy!
Example: Jag skulle läsa om hon lyssnade.
I would read if she listened.
You can do the same thing in more complex constructions. "Would have" can be directly translated to skulle ha, which is followed by the perfect form of the verb (like läst or kommit), just as in English.
Example: Jag skulle ha läst om hon hade lyssnat. I would have read if she had listened.
Vore
Vore is the conditional form of the verb vara -- to be. It is actually derived from the archaic past subjunctive mood that once existed in Swedish (and still does in a few set expressions). Although there are some nuances, for now you can use vore just as you would use skulle + any other verb. Because vore already includes the conditional aspect, it would be redundant (and grammatically incorrect) to say skulle vore.