It will depend on a number of things. If you've been to an old-world service (Latin Catholic, Orthodox, Anglican, Lutheran, etc) you'll find much of the worship service familiar. Outwardly the service is very similar, with notable exceptions being the lack or ornate decorations, statues or imagery in the sanctuary of the CoE.
All of the old-world services have components that are derived from temple Judaism and other aspects from synagogue worship, as is expected. The study of the history and symbolism behind certain things are intense and beyond the scope of this post. Theologians can specialize in that area.
Four of the five "parishes" are Aramaic only services. The liturgy is usually classical Aramaic, and the readings and sermon are usually in Neo-Aramaic koine. The fifth church, St. John, is a missionary parish and has a mixed Classical/Neo/English service. The "priest" says the sermon in both Neo-Aramaic and in English, repeating each sentence while alternating. Parts of the liturgy are in classical Aramaic, and parts are in Neo-Aramaic, while other parts are "targummed" into English.
As a American Pentecostal, you'll find very little that is familiar. I'm literally talking the other end of the spectrum. Women are quiet, other than to sing in the choir. Their hair is covered with a scarf. It's very solemn. Incense continually fills the area. There are about a hundred times that the sign of the Cross is made during service. There is the "Eucharist" with the Bread and the Chalice of wine. There's a lot of prostrating that might remind you of Islamic worship. No one is flipping pages of the bible during the sermon, as the purpose of the service isn't a bible study. Etc.
I think Akhan Chuck can attest to the above, having first hand experience <!-- s
--><img src="{SMILIES_PATH}/wink1.gif" alt="
" title="Wink" /><!-- s
-->
Having set your expectation properly, you are always welcome. Baptized Christians are welcome to participate fully, including the reception of the Communion, if they so desire. The "priest" may ask if you are baptized before offering the Communion bread, if it's the first time he sees you in line.
That's about it. <!-- s
--><img src="{SMILIES_PATH}/smile.gif" alt="
" title="Smile" /><!-- s
-->
+Shamasha