Start out small and increase your garden as time allows.
Many people start too big and become overwhelmed.
Depending on your time constraints consider plants that are relatively carefree versus plants which are not. For example, daylilies which require very little care while roses need much attention. If you've just moved into a sub-division chances are the developers removed all the top soil before they built your home. If it needs to be improved, start with small section. Consider composting to improve your soil.