You have to tell us about yourself. You tell us where you are now and where you want to get to, and then we can advise you on how to get there.
- What is your height and weight?
- How many pushups, situps, squats and inverted rows can you do?
- Can you run 5km without stopping, and if so how quickly?
- Can you touch your toes, and touch your hands together behind your back, one from underneath and one from the top?
- Do you have any dietary restrictions, anything you cannot or will not eat?
- Have you done sports or any other kind of physical activity in the past, if so what, how much and for how long?
- Can you join a gym (can you afford it, is there one close enough, etc), and/or can you get some home gym equipment?
- Exactly what do you want to achieve with an exercise programme? Lose fat? Gain muscle? Strength for some sport? Improved flexibility? Better health? Big chesticles? Or...?
If you cannot do 20-30 each of pushups, situps, squats and inverted rows, run 5km without stopping, touch your toes and your hands together behind your back,
then you need to build up to that. I give advice to a beginner on achieving that
here. There is included general dietary advice, too.
Once you can do that, or if you can do it already, then take a look at
stronglifts. This is a simple programme that you can download for free, and you should be able to follow with most gyms' equipment, or with your own equipment at a cost of around a year's gym membership. It will develop basic strength and put on some muscular weight for you, if you give it consistent effort.
Of course that's if you want strength and size... we don't know yet.