If I start paying on some of my debts that show on my credit report, How long will it take to show improvement?

I want to start paying my debts to fix my credit score, I’ve been interested in becoming a police officer but my credit is terrible, which they do check. If I start paying my debts how long will it take to show any improvement? Is bankruptcy a good idea at age 27? http://bit.ly/lbXHb0