You are engaged, Congratulations!! Now you must get that guest list together. It is necessary to get guest list from your parents, your fiancé, and of course your list. It is necessary to have the guest list as this will assist in size of ceremony and reception venue needed.
Create this list and keep adding for a few weeks. As you share your news so many people, (friends current and past, relatives, coworkers) will want to be invited. Add them to the list for a few weeks.
Now about two months later you will need to review that list. Review the list and begin removing those you really do not want to invite. There are many reasons you may remove a person. This is for you to decide, there is no need to justify this to that individual or anyone else. This is your wedding.