Every person who has had any success in the fitness industry sells their workout plan. If you ask them, they'll likely tell you that theirs is "The Plan". So if theirs is the perfect one, why are there so many others claiming the same thing? The answer is, every person is different and needs or wants a different type of workout. Our motivation, attention span, and interests all influence what sort of exercise we enjoy doing and especially what we'll stick with. Some people want a higher pace and constant change, others like a very regimented routine. This is the reason why there are hundreds of formats, videos, and approaches. The determining factor is really whether or not you will do it, consistently.
So how to choose the right form of exercise? I suggest trying a variety and see which one seems to feel the least amount like an obligation. If you've recently joined a gym, try all of the classes that work with your schedule. You are bound to find one that you like. There are also tons of online options available. It is important to have a variety cardio, weight-bearing, and flexibility based workouts. The important thing is be consistent. No matter what you choose, if you do it consistently, your body will respond positively.
Don't be afraid to try something new, you might just like it! You need to move everyday at a pace that makes you breathe hard and sweat. Start small and work your way up. Try everything until you find the right thing for you. Doing something is always better than doing nothing. Good luck, have fun and no matter what, just keep moving!