There is no better time of day to work out unless how you time it makes it more pleasurable and therefore makes working out easier to stick to. It's a lifestyle not a race.
Premeal is not as important as the work out. A shot of protein and carbs is fine.
If you want big arms and a big chest, look up compound exercises and make them a large part of your workouts. It is impossible to do weighted squats, lunges, dead lifts without using your arms and chest.
You can look up exercises that target muscle groups here under the exercise heading. They are fine but hitting every muscle in your body will make you strong all over.