I myself have only been attending the Episcopalian church for a year, so I'm sure there will be more helpful people able to answer. However, I can identify as I was in your place not long ago! Also raised Methodist, attended private Christian school.
I say to just call the church. I was just talking with our Canon this morning because I had some new questions. Just ring the office number and someone should be happy to help you. That's what they're there for! Ask about the nursery situation, which service would be best to attend, etc. Each church is different, so it's good to find out what they do specifically. At my church, there is a service that's more for families and one that isn't on Sunday mornings. But anyone can come to either and children are always welcome during service, even though there is a nursery and Sunday School.
As for what to do - don't feel nervous. My parents are Catholic and I attend mass with them sometimes. I find the Catholic church much more rigid about the rituals. I love that the Episcopalian church has those rituals and the tone is still very reverent, but it's completely ok if you don't do everything exactly like everyone else. In fact, when I look around, many of us are doing it differently. Maybe we all read different Episcopalian 101 sites!
Have you been baptized? The church recognizes any baptism. No need to redo. If you have, you can take communion. Just follow everyone else up in line, kneel at the alter, put your right hand, palm up, over your left hand, and receive the bread. You can eat it right away or dip it into the wine. I eat mine and then when the wine comes, hold onto the challis and help the Priest guide the cup to your mouth. I say amen after the blessing, cross myself, wait until the person beside me has drank from the cup, and then walk back to my seat. If you don't want to take communion, you can just stay seated in your pew or go up, kneel, cross your arms over your chest, and receive a blessing. That's always nice. I take my dd up with me and she receives a blessing.
Just relax, take time to pray and do your best to follow along. By and large, it's a very welcoming and friendly church. Give it a shot if it feels right to you. As for the community outreach, I know of NO other church in my city that does more than the Episcopalian church. Very outreach, charity oriented. Service oriented, not to proselytize.
Good luck! I hope you love it like I do.
Sarah - mama to the love of my life, Aurelia Josephine, b. June 11, 2010