Dee; Your concern about the church which I posited as likely one of the very first churches in Christendom, may well be something you should look into.
Please understand, archaeology is not a 100% proof endeavor..it is more a detective work..utilizing evidence;.. allowing very convincing evidence and discarding questionable evidence.
Before DNA, many a person was given a capital sentence, by the same investigative methods.; possibly in the same jurisdiction where you were employed.
...And DNA can be questioned in some circumstances.
There is much to enjoy about the history and nuances of Christianity, throughout the very early years, up through it's struggles, persecutions and victories of the last 20 centuries.
That article I posted should in no way alarm you, nor will it have any negative effect upon current potential converts. In fact, it may encourage those with an enquiring mind to pursue a closer relationship with Christ AND a deep study of Christian theology, archaeology, philosophy and thought beyond the Bible alone.
Yes, the Bible should be the primary source and handbook . ...But there is such a wide world of related knowledge to pursue, that a serious Christian would have to be
lethargic and quite droll, to pass up the chance to learn more.
I would be pleased to address your concerns about Biblical subjects at any time; that is providing we can confer in a respectful, non-accusatory manner.
Meanwhile; here are a bevy of scholars, discussing that "first church" you are so concerned about...
First, the Biblical Archaeology Society..a group of scholars who are there and work at these discoveries every day.
https://library.biblicalarchaeology.org/article/church-of-the-apostles-found-on-mt-zion/ Next other professional persons or groups involved in the same profession;, all in agreement;
http://centuryone.org/apostles.html https://jamestabor.com/church-of-the-apostles-found-on-mt-zion/ https://www.researchgate.net/publication/307582585_The_Ancient_Church_of_the_Apostles_Revisiting_Jerusalem's_Cenacle_and_David's_Tomb .....Plenty more where those came from, ...if you need them..