Sores usually are blisters but they can present in different ways. Sometimes they start out as a paper-cut looking lesion or an open, circular sore.
It can be one single sore or a cluster or multiple sores spread out.
While it usually is some type of sore, I don’t think an abrasion/rash type area is unheard of.
There is no golden rule. If it’s going to present skin symptoms, what is most recognizable is blisters or lesions. But it presents differently person to person. Blisters are most common though.
Usually a first outbreak (a primary) is at the point of virus entry. With heterosexual sex, it’s the penis or vagina. With homosexual sex (m/m), it’s the penis or anus.
With recurrences, outbreaks can happen anywhere in the genital region, the anus, even the thighs or lower stomach.
While it’s not impossible for a primary to be a spot where no contact occurred, it would be unlikely.