Unlike the case with many other languages, you cannot travel anywhere to speak, hear, or read Latin. There are no menus, bus schedules, or phrase books written in Latin. So, where do you go in order to find Latin? Well, almost all of the real Latin — as opposed to the exercises in this book — exists in the works of ancient Roman authors. Appendix B includes a list of some sources of Latin writing that you can use to challenge yourself and further your understanding of the Latin language.
What can you do, besides reading “real” Latin, to keep your skills sharp? Now that you've had a basic introduction, one thing you can do is get a more advanced, “traditional” Latin textbook, then work through it from beginning to end. You'll be impressed at how much you understand, though being exposed to a different perspective will also add to your knowledge of Latin.
Another thing you might do is to get in the habit of stopping occasionally to analyze an English word for its Latin elements. (This is often more convenient than pulling out of stack of vocabulary flash cards, although flash cards have their place!) Finally, if you are reading something in Latin, you can always translate sample sentences into good English; then, translate those sentences back into Latin, comparing your result with the original text. This sort of exercise will assist you more than you might think in refreshing your knowledge of certain grammatical points.
Finally, congratulations are in order. For approximately 2,000 years, Latin has been part of the West's educational system, and you are now a part of that tradition. You won't receive any medals or prizes, but you should feel enormous satisfaction at having acquired a solid understanding of Latin, as well as a greater appreciation for the beauty and complexity of the language itself. You are now fully prepared to continue your exploration of Latin and the people who spoke it.