Hi Joan,
Don't worry - its a lot to get a handle on but Disney can been done on a limited budget. Your 2 year old gets in free so your savings have started already.
Gone are the days of ticket books where a separate ticket was needed for each attraction. Now a park admission ticket includes unlimited use of all rides and attractions. There are some special experiences within the parks that are extra (i.e. The Pirates League or BBB).
I'm not sure how many days you plan on staying or what your budget is but the admission price per day goes down the more days you purchase. For example a one day one park adult base ticket is $79 (always subject to change) but a 5-day one park per day adult base ticket is $228.00 which averages out to $45.60 per day.
I recently answered a question regarding some money saving tips while eating at WDW - click
here.
Make sure you bring your own rain gear and sunscreen. Take advantage of free activities at WDW like walking around DTD or Boardwalk. Fortunately your son is not quite old enough to beg for tons of souvenEARs so don't go overboard purchasing them - he won't know the difference. Sometimes the best souvenEARs are the memories you make together.
Wishing you many magical memories :-)