Dean, a small-town charmer, bravely leaves his home for the bright lights of Los Angeles, only to be greeted by sex, lies and deceit. OR In pursuit of his dreams, can a small-town charmer overcome the temptations in a city he doesn’t belong in or will he become another casualty of L.A.?

After leaving his small town in pursuing luck in L.A., reckless dreamer finds himself in a center of sex, lies and deceit, and to not become another L.A. casualty, he must now -

Dreamer is a much better word

"Small town, meets big city, gets corrupted by a downward spiral of partying and drugs" is a very standard film concept.

There is nothing wrong with the fact this basic idea has been done, it's just for your idea to work it needs a hook, something that makes it stand out.

Add a hook to the logline and it will be greatly improved.

Hope this works out for you, good luck.