The quote is basically saying that based on your education, is how far you will get in life or how well. Alot of successful jobs look for people with a great education. And in order to succeed tomorrow you have to work for that success today. For example is you had a test tomorrow you would need to study today to succeed on the test tomorrow and get a good grade. but if your slacking off and not doing the responsibilities of today, you will have to work twice as hard tomorrow and won't get to enjoy it. So when it says that tomorrow belongs to those who prepare for it today, they are basically saying that by doing the responsibilities of today, you can succeed from it tomorrow
