Exercise Idea's

Any body weight excercises (push ups/ sit ups/Squats/lunges)
Yoga type (plank).
Cardio can be done easily by dancing... Not just kind of move but get yourself sweating.. maybe look up zumba on youtube?
Or jumprope/if you dont have a jumprope you can lay something small on the floor and jump over it side to side and front to back then
Do squats or lunges in between sets.
Dips (use something sturdy and use your arms to lower yourself down and back up) or even wall sits (back against the wall in a sitting position, hold for as long as you can).
Pyramid excercises.. (pushups - 1 pushup, roll over and do 1 arm press into the air, roll over, 2 push ups, 2 arm presses.... to like 5 and then back down)
High knees/butt kicks/jumping jacks
Burpees
Mountain climbers
Bicycle
Flutter kicks
Supermans (hold 1 hand and opposite foot in air while laying on stomach, switch sides)
Not sure the name of this one but hold on to under your door or bed while laying on your back, bring your feet up to the door/bed using your abs to lift and back down
If all else fails, use canned goods for light weights..

There's a ton more just cant think of them off the top of my head
Hope this helps

Check out YouTube's BeFit channel. Tons of workout videos.