Answer: Asparagus is a perennial, meaning it will grow for many years in the same spot. Be careful not to till it up if you want to keep it! Nearly all other vegetables such as tomatoes, squash, greens and so on are grown only for one season, as annuals. (A possible exception is garlic which may be planted in the fall or the spring.)
You are not too late at all. Since you are new to this I would suggest you look at a book or two about vegetable gardening. One I particularly like is "Vegetable Gardening for Dummies" by Charlie Nardozzi, Dummy Press, ISBN 0764551299. In it you will find lots of practical advice including information about soil preparation, planting and caring for your veggies. You can also search the Q&A for lots of good information.
In the meantime, you should run some basic soil tests to see which amendments you might need to add -- or not. The secret to having a good garden is in the soil preparation so this is not something to skip. Your county extension (745-3445) should be able to help you with the tests and interpreting the results. They might also be able to suggest vegetable varieties that do particularly well in your local area.
Enjoy your new garden!
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