If I plead guilty and pay a fine do I still get charged or are the charges dropped once the fine is paid?

Generally speaking to the limited facts presented:

First, you should hire a competent attorney licensed to practice in your area, and fully discuss the details of your case with that attorney.

Generally, when you first appear at a misdemeanor worthless check docket hearing, the prosecutor will discuss options with you.  Sometimes, if you have the full amount of the check with you and are able to pay it that day, they may agree to dismiss the charge.  They may not agree to such.  If you have a "plea deal", generally the Judge will accept it.

If you plead "guilty", the charge is not dropped, as you have plead guilty to the charge, unless your jurisdiction has some form of program that requires you to first plea guilty and withholds adjudication until it is determined that you either did what you were required to do under the program or failed to do so.

Again, you should fully discuss this with a competent, licensed attorney.