Rahima...I have 2 suggestions since you mention Lake Sailing and not wanting to invest 5 figures.
1. Buy a small car topper sailboat that you can take to the lake and mess around with till you're sure that you and everyone in the family want something more. Try this link as an example... www.castlecraft.com/sailboats.htm
2. Buy an old and cheap 20-22 footer on a trailer. You should be able to pick up somethinng serviceable for $2-3K and you can work on her in your driveway while having something serviceable to use on the weekends. When you go to sell, you'll get most of your $$ back.