Live to Inspire's answer is great.
A longer answer...
It depends on how fit you want to get and what equipment you have. I will assume you have no equipment and list exercises with varying degrees of difficulty (in the order I would perform them):
Jogging on the spot: land on the ball of the foot to avoid injuring the heel; will be good for working the calves
Bulgarian squats: again with a bag of books for added difficulty (see YouTube if you aren't sure how to perform these)
(Front) Squats: you can make these tougher by filling a bag with books
Burpees: I'd get on YouTube for a decent description to avoid injury
Push ups: vary difficulty with wide, narrow, elbows at the side; raise the feet on a chair for a tougher work out
Shoulder presses: fill a bag of books...
Tricep dips: between two chairs
Turkish get ups: grab that bag of books again and check out YouTube
Leg raises: lie on the floor, raise legs then get hips off the ground to work the entire length of the abs.
Mountain climbers: imagine the floor is a wall and you're climbing up (across) it so get on all fours with only your hands and feet making contact with the floor