In order to improve, you should definitely practice any changes to your swing until the become automatic before trying them in a game. However, making changes can be difficult if practice is simply hitting a bucket of balls at the local driving range. In order to really improve, you should have a practice plan that can help you work on specific areas, and you should film yourself as much as possible so you can see the changes as well.
If your shots are going repeatedly to the left of target, or conversely going to the right, then the problem is with your grip. If your grip is too strong then you will have your hands too far to the right on the club which causes a hook and if they are too weak then your hands are set too far to the left causing the ball to slice.
Golf bags are usually classified as cart bags, travel bags and stand bags. Each kind of bag will have its pros and cons but in the end, it is your preference that should be given utmost consideration. For example, a cart bag is larger and heavier but it has more compartments and is roomier for just about everything that a person may want to bring with him or her throughout the day.
One of the other benefits of private lessons are that they usually include video recordings of your swing. This may be done periodically as you progress, or the instructor may tape each and every practice session so that you can watch yourself more closely. Doing this will help you to develop muscle memory and will help you to feel the feedback your body is giving you while swinging.
Tension is the enemy of golf, and we are at our most venerable whilst addressing the ball. We must focus on being completely relaxed if we have any chance of hitting the ball a fair distance. Stay loose and keep moving. Now I don't advocate you start dancing around but instead just keep certain parts of your body active.
If you find cost to be the most prohibitive factor in choosing private lessons, you may want to consider group lessons. These may be offered by the same golf pro who teaches the private lesson, but because several students are learning at the same time, the cost is less for each student.
How far should you be standing from the ball? Simply stand up straight with your arms extended whilst gripping your club in a neutral position. Now bend from the hips until the club head touches the ground then lightly bend your knees and relax the arms.