What is a good way to work your lower abs?…. any other workout/diet tips?

I really need to get into shape. If anyone can help me with anything… diet advice, workout tips, how to work my lower abs, my upper legs, ANYTHING really. I have 24 days until we go to the lake and I need to be in a lot better shape. I need to tone my muscles, lose weight, and better my body body… seriously… ANY help would be great! Thank you in advance!
OH… and I would really like things I could do around the house… not have to go to the gym for… even though I do have a gym membership. :-/