I don't have the number handy but if you just do a search for T.R.S.A. or just type out the words Toms+River+Soccer+Association, you'll find that the dues are just $22.00 monthly. Not a bad deal really!

Or did you mean the standard METAR version "thunderstorms and rain"? You should really avoid contact with those!

TRSA?? That's a VFR thing right?

Airspace is broken down into classes; A-G and for some reason they skipped "F" ???.....
Before that, they were designated as a TCA, PCA, ARSA, and if memory serves my correctly......there was also a TRSA. All of the others have been eliminated and a definition for a TRSA can still be found in a current FAR/AIM or Pilot Controller Glossary. This term simply refers to the radar service which is provided by a B,C,D or ARTCC(air route traffic control center) facility. It is only used for aircraft flying  under VFR. If you're asking how to do it on the SIM, I think you need to compile a flight plan and then request a clearance.
In real life, you would try and find an ARTCC frequency(Miami center, L.A. center, Indy center etc. etc.) and do what is known as a cold call BEFORE YOU HAVE ENTERED THE CLASS B VEIL AREA OR C AIRSPACE. If you are flying in real life, for the love of god, PLEASE cold call first. A cold call(since you asked)is just a radio call that starts with the controlling agency's name and ends with your callsign, no other information is announced. The reason that I may seem so adamant about the "cold call"  is because I hear it everyday when I'm flying(the wrong method of calling that is).  All day long(especially on weekends) I'll hear....."aaaaahhhh  Albuquerque center this is... a ...Cherokee eight five two five bravo ...were a hunert a sixty five point two miles from the Lampass-sass VOR and we'd like some radar service to Seattle via... ahhhh... El Paso... uumm.. L-A-X ...errrr.... Las Vegas.... aaaaaaa ... Core Dee Allen, that's in Idaho!.... and then directly to Boeing field... aaahhh over......!" And most of the time, the controller will respond to all of that with "aircraft calling.......I believe it was a Cherokee....say your request??" What that does is fill the airwaves with a LOT of unnecessary chatter.

Now, when the controller responds to the cold call, you answer with: who you are.....where you are......what you want.
An example in your specific case would be,  you--"LA center, Cessna 54HB".......LA center--" N54HB, LA center, go ahead".....you--""54HB is five zero miles south east of LAX at four thousand five hundred, request flight following to Paso Robles."

That's how you get your foot in the door.

ARTCC frequencies can be found on most charts(especially IFR charts), in an AFD(airport facility directory)or in any of a number of privately published books or charts(Pilot's Express, Acu-Kwik, AOPA Pilot's directory etc. etc.).