You will not have "more classes" per day, per se. More than likely, you will still have 5 courses 1st semester of 4* year and 6 courses 2nd semester.
Where validating comes in handy is typically later on in your cadet career. Validating X number of classes means you can take X number less during some future semester (not less than 4 per semester, though). Alternatively, you may be able to replace the X classes you validated with X classes toward a foreign language or other minor. Essentially, validating helps free up your schedule to add more classes or have a lighter workload later on.
However, it is also a double-edged sword. If you "accidentally" validate a class which you are not truly proficient in, it may very well come back to bite you, especially if it is a subject intimately related to your major. For example, "accidentally" validating Calc 1 may seem like a boon, but if you then declare an engineering major with a heavy math emphasis, you will probably wish you had retaken Calc 1 instead of skipping it.
Keep in mind that not validating is not a bad thing. When I first came here, there were at least 1-2 classes I could probably have validated and yet consciously chose not to. They were very technical classes closely related to my major, and I ended up not regretting my choice. Plus, being familiar with the subject material will pay dividends when the homework piles up and everyone else is taking twice as long to do the same problems...
So in summary--do your best on the tests, but be careful about trying to skip majors-related classes you aren't proficient in. And don't stress about it. I would venture to say that most people don't validate much (if at all), and yet they typically do just fine. Yes, they're busy, but your schedule will be busy whether or not you validate...
Good luck!