Yes, genital herpes can lay dormant or remain asymptomatic (initial outbreak may be so less that it can go unnoticed) for very long durations. See here in this authentic resource, where it says, it can remain dormant for 40 years.
Your follow up questions are welcome.
As I mentioned, the first outbreak may be so mild that it may go unnoticed. As you can read in the resource (site from the mayo clinic), I had sent you, most of the people never know they are infected because of absence of signs and symptoms. But it can cause symptoms very late. The infection remains life long and may never be symptomatic.
Oral antiviral medication may help you. This can shorten and prevent outbreaks during the period of time while taking the medication. Do not worry.
This is one question which is difficult to answer. The only way to know about the infection is by two ways;
1) Either by the signs and symptoms
2) Or by the investigation.
If there were no symptoms, we assume that it was dormant.
It is impossible to predict the time of infection except your sexual history. There is always a possibility of babies getting infection during delivery, so cesarean is planned. But infection is rare in babies. Read here under the heading, "what are the complications of genital herpes";
Yes, this can be first outbreak, but again cannot be 100% certain.