A Dodge Neon use DOT3 brake fluid.
DOT 3
Dot3 or Dot4
Brake fluid is added to the brake master cylinder reservoir, under the hood on the driver side.
DOT 3 is the required fluid.
Master cylinder low on brake fluid or parking brake not totally released
It gets added to the master cylinder located drivers side of the firewall
Either you're low on break fluid OR your parking brake is set. In either case, it must be repaired.
Look on the top of the reservoir cap. There you will find what kind you need, more than likely you use Dot 3 type brake fluid.
in the brake fluid reservoir usually located under the hood. If you are unfamiliar with this are as it sounds you are I would take it to a local jiffy lube or mechanic where they have some idea about what to put in and where to put it.
it is usually the rear brake cylinder that's leaking and needs to be replace on that side.
A 1999 Dodge Neon uses ATF+4 Type 9602