that depends a lot on the degree who which the person is overweight, their age and health status and their current level of ability.
If people are severely overweight and have already health problems because of it, aquatic exercises are often the best place to start. In a case like that, I always require a physician’s approval for exercise. You will also need to follow the guidelines established for any such medical conditions in terms of frequency, intensity and recommended duration.
Younger people who are obese often have not yet developed the problems associated with obesity and may be quite mobile. On the assumption that weight loss is a goal, the person should do regular cardiovascular workouts in addition to some resistance training.
Generally speaking, there is not one correct answer here, because ‘obese people’ by itself is not a description of an individual. It will be best to do an assessment and take it from there. You should also ask the person for input; after all, they are the ones who will be doing the exercising. Ask for preferences and dislikes and try to structure the workouts around those.
Of course you should check with a physician first, but walking is usually safe. Start slowly; a comfortable pace for up to 10 minutes if you can tolerate it. Once you can do 10 minutes easily every day you can increase the time, increasing about 10 percent a week. It is ok to break it up into several mini sessions a day. I would also recommend finding a qualified trainer and adding strength training sessions.