Exercise doesn't require expensive equipment, a gym membership or a ridiculous infomercial invention. There are 3 very basic body weight exercise that will give you good results and a great foundation to work from. The exercises I am referring to are push ups, squats and plank.
All 3 exercises have variations, particularly squats and push ups, which allow you to mix things up and vary the results. There are numerous progressions and regressions for these exercises, so no matter what your level of strength and fitness, there will be an entry point to these exercises. By simply changing hand placement, adding weight, moving the position of your feet, lowering the knees, you will be able to vary to difficulty and results. There are many more ways to vary these exercises, all of which can be found with a quick internet search.
If you want results, convenience and to avoid spending a lot of money on gym memberships or gimmicks, kick off your exercises routine with these 3 exercises. It wont just be a starting point, but the chance to build a strong foundation of fitness for more challenges ahead. Of course seek advice from a medical professional if you have concerns about starting any of these exercises.