The first thing you might want to do, Jacqueline, is record information you already know -- since you may in fact be one of the few people left alive who does know. Things like your parents' and siblings' names and birthdates, and where you all lived when.
WikiTree is a great place to record that information, since it is open to the public and free to use for all time.
Once you get your immediate family members recorded, then you can start looking for connections to our main tree, being careful to make sure that any connections you make are supported by source documents.