One of the most important elements in developing awesome pronunciation in your target language is to train your ears well enough to self-correct when you say things out loud. If you can hear the difference between "caro," "carro," and "Car-O," then you're going to notice when you say "caro" when you mean "carro," and you will correct yourself. Once you develop that crucial skill, everything else can follow -- primarily through mimicry.
A great practice is to go through the trainer and repeat each example word out loud as you learn it from the spelling rules. Every time you repeat those example words in future repetitions, you're going to be doing it more and more accurately as your ability to self-correct gets better and better. Minimal pairs can be harder to repeat at first. If you can't hear the differences between the words or phrases yet, give it time; you'll get there, and as soon as you do, you should start repeating them out loud.
If you are familiar with IPA (especially in terms of mouth/tongue positions), it might be valuable for you to go through the videos one more time, 10-14 days after you begin the trainer, just to review that content.