You might choose to give different sections of your family their own tree, but if you change your mind about this later then Gaia's merge feature will help.
If you've collected a lot of data then the tree will become more difficult to browse, but the program offers multiple views (Complete, Linear and Pedigree) to help you zoom in on the data you need. Define their relationship to each other and the tree will begin to form.
In a few moments you can begin adding the key details about yourself and your family: names, birth dates, places and so on. Gaia Family Tree is a simple genealogy package that makes it easy to start building your family tree.