Having a sound understanding of the ball flight laws is crucial, if you want to improve your swing in any respect. If you know what your typical ball flights are, you can conclude what you are doing during your swing. As the famous golf teacher John Jacobs said: Golf is what the ball does. Go on the internet and open some books. You should know what a push, a slice, a pull, a draw, a fade, a push-slice etc. is. (Or read about the ball flight laws here)
And you should know which kind of swing and which address position supports these shots. If you have not bothered with these kinds of details as of yet, it can become quite confusing. Just study one shot at a time and try to understand where it is coming from. After you have worked your way through all the information take a good hard look at your own swing and setup.
First think about where your ball goes most often when you are miss hitting it. Is it a slice? Is it a push? Write your thoughts and the things you learned into your golf journal. Which swing faults are most likely producing these faults? What can you do to correct them? Ask yourself these questions to get on the right track where you need to go with your swing.
The nice thing about knowing the in and outs of the ball flight laws is that you can become your own swing guide to some extent. If you are working with your local pro, discuss with him what you found out. I think he will be glad to hear about your effort and your new knowledge.
Study the ball flight laws on the internet and with the help of books.
Find out what kind of swing produces each shot.
Terms like pull-hook or push-slice should not be a mystery to you.
Take a look at your own swing and think about possible corrections.