Hello Terry and welcome to the forum,
It is great to hear you wish to become a Muslim, which is indeed the way of life that Allah has chosen for mankind. Becoming a Muslim is very easy. It is done by pronouncing the testimony of faith (the Shahadah), with sincere belief and conviction.
As for the two testimonies of creed, the first is
"ash-hadu an laa ilaaha illa allah"
(I testify that there is no deity other then Allah), which means that one believes and confirms that there is nothing to be worshipped other than Allah and that one is prepared to implement His divine rulings and guidlines (shari'a) for all aspects of life. The second is
"ash-hadu anna muhammad ar-rasool ullah"
which means the belief that Muhammad (peace be upon him) is the seal of the prophets (i.e. the final one), whom Allah has sent with the Islamic religion to supercede all other previous religions and that it is obligatory to comply with what he has enjoined, and to abstain and renounce all that he has prohibited and restrained.
Some further information at these links:
http://www.islamreligion.com/article...FUEb4QodwHxFCg
http://www.beconvinced.com/archive/e...s%20Of%20Islam
I was trying to find a clear video of someone reciting the shahadah, and so far I have found this (don't worry, it doesn't have to be on stage in front of so many people! It's just the words I wanted you to be able to hear):
http://www.youtube.com/watch?v=Jh3m2iYEmwU
Regarding the Mosque, there is no reason why they should think you are not being serious. People of all ages and backgrounds convert to Islam, so I am sure they will be very happy to welcome you to Islam (as will we!). Try to contact someone from the Mosque as soon as you can and they will be able to provide you with further support and advice.
Please let us know if you need anything. May Allaah :swt: open your heart to the light of Islam, Aameen. :)