Also the age when shidduchim start may vary by community.
The first recorded shidduch in the Torah was the match that Eliezer, the servant of the Jewish patriarch Abraham, made for his master's son Isaac (Genesis Ch. Abraham gave him specific instructions to choose a woman from Abraham's own tribe.
The prospective partners either date each other or in stricter communities they go to a "bashow" or sit in.
A typical bashow scene is that the young man with his parents goes to see the young woman in her house to see if the prospective couple are compatible.
After the match has been proposed, the prospective partners meet a number of times to gain a sense of whether they are right for one another.
The number of dates prior to announcing an engagement may vary by community. In stricter communities, the couple may decide a few days after originally meeting with each other.