@albatro55 Simple Answer: No, it's not enough. Just training a single exercise for a set amount of sets and reps will only get you good at doing that single exercise for that amount of sets and reps. If you only do 7x5 incline pushups, you will become really good at doing 7x5 incline pushups. That's about it.
Here's all you need to do:
1) Pick a workout routine that you can stick to long term. There's the Recommended Routine in the sidebar here, or you can go to /r/fitness if you have access to weights. Be honest with yourself, what types of workouts do you like more (weights, bodyweight/calisthenics, martial arts, etc). Try to stick to that. Doing exercises and workouts you enjoy will ensure long term adherence (funny how that works).
2) Figure out your diet situation. If you want to lose weight, eat at a caloric deficit. If you want to gain muscle, eat at a surplus. No more than 500 calories in either direction. Keep protein at 1g/lb body weight, fats at 20-30% total caloric intake, and fill the rest in with carbs (yes carbs, your body needs energy to workout).
3) Reset your expectations. No one gets results in a short period. Literally no one. This isn't a situation where it's possible but unhealthy and we're just sitting on some massive secret technique to get shredded in a week. It's just straight up impossible. Doesn't matter how bad you want it, the laws of physics and physiology aren't going to change cause your feelings are hurt. Set a 3 month timeline
MINIMUM (preferably 6mo-1yr) for results. Muscle grows when consistently exposed to a stimulus it cannot perform to. Fat is lost when your body is consistently in a caloric deficit, and needs more energy than it uses, so it burns up your fat stores. See the common word there? Consistency. This shit takes time. Give yourself that time.
4) Track progress, starting now. Start with some "before" pictures of yourself, and body measurements if you're more of a numbers guy, and continue to take pics/measurements every few weeks. It helps you track/see progress, especially at the beginning. You're not going to magically shed fat and grow a ton of muscle overnight. It's going to be slow and steady progress that you likely won't see at first. The pictures help with that.