Start at the beginning. First thing you'll need is some decent sneakers. The you'll need to start a regular cardio routine. You can walk outside for free, or you can look into joining a gym. You can try working with a trainer, ir see if they will show you proper use and form of the equipment. This site has great videos that will show you how to perform weightlifting and other exercises.
Take it slow and steady, make it a part of your life from today forward and have a good time.