I see the local church lists Orthos and Divine Liturgy. What are these and which would be most benefit to a visitor to attend?
First of all, many of the Orthodox have left the FR in recent years. There are a handful left, one or two Greeks at most.
I am cradle Serbian Orthodox but I am not a practicing the faith. I don;t hate the Church or God. I just don't know what God is (that's another topic). However, I do know a great deal about the faith.
To answer your question: the prayers before the beginning of the liturgical worship and the liturgical worship itself. The orthos are the equivalent to "matins" or morning prayers. The divine Liturgy is the Eastern name for the Holy Mass.
You would benefit mostly form attending the Divine Liturgy, but I suggest you read up thoroughly on it, or else it will be a meaningless, ritualistic show. Get informed.
Needless to say, with the exception of a couple of Orthodox posters, most of the information you received thus far is either distorted or outright incorrect. I suggest orthodoxwiki.com in absence of a well-informed Orthodox Christian.
Contrary to one poster, the RCC and the EOC does not have a dispute over the Holy Trinity; both Churches teach exactly the same thing about the Triniatrian God. The dispute is in terminology as regards the 'procession' of the Holy Spirit mentioned in the Nicene Creed.
The addition "and the Son" is a latter-day addition which the East rejected and for a good reason. Since the, the RCC has made it clear that they recognize that the Spirit, as regards his existence, proceeds form the Father, thereby recognizing the monarchy of the Father as the source of everything including the divinity (or Godhead).
It's a lot more complicated than some of the superficial answer your received. The Orthodox Church is every way a catholic and apostolic Church, with valid clergy and sacraments, as the Roman Catholic Church is. They form two traditions in the one holy, catholic and apostolic Church, and were in communion for the most of the first one thousand years of Christianity. They have not been in communion for all practical purposes since 1054 AD.
The reasons for this are many and complicated. But just remember that as far as apostolic authority goes, the Orthodox East is no different than the Latin West.
The Orthodox East also rejects Augustinians original sin, Immaculate Conception, Papal infallibility, Purgatory, unleavened Eucharist, etc. as innovations unknown to the early Church.
All Eastern Orthodox share the same theology and faith and are in communion with the Bishop of Constantinople or new Rome (aka Ecumenical Patriarch), who is second in honor after the Bishop of Old Rome (aka Pope). Members of any particular EOC can receive communion in other EO Churches.