Overall, you did amazing! I can understand everything you said, however you did have some trouble with grammar. That's completely fine, as even native English speakers make mistakes!

You've done a great job expressing your excitement and needs regarding English language practice! Your clarity in conveying your comprehension skills and the areas you'd like to improve upon is commendable. As you plan your trip to the United States, I recommend seeking out opportunities for conversation. Engaging with native speakers will bolster your confidence and enhance your speaking skills. This application is a helpful starting point, and I'm sure you'll benefit immensely from it. Safe travels and best wishes on your language journey!