Okay Debbie. I've wanted to answer this question for you yesterday, but my account wasn't validated yeah. So now, I'm ready.
I'm going to give you my feedback as a musician on a worship team.
I've played for the junior group for a while, at a couple local worship events, and I used to play for sunday worship. Yet, I had only six-seventh months of professional piano experience through a pianist with a masters. It was way too expensive and I couldn't afford it. However, I was also playing the clarinet from middle school to high school. I used what I've learned what it means to be an ensemble and applied it to worship band. In addition, I have had local, asian musicians teach me other asian music stuff. In summary, it doesn't matter who you are, and if God leads you, do it. I'm just sharing my tips from what I've done in the past as a keyboardists.
1) Don't limit your creativity. There's a reason why, unlike myself, why you can play all fifteen scales. If you think a particular song need just riffs, play riffs. If it needs just chords, play chords. I would listen to the song and imitate it as much as possible. If it needs more or less stuff, you are the musician - the artist.
2) So what if it's just a drum and piano. Jazz it up. More importantly, communicate with your drummer. Compromise and ask him what you'd expect. In a song like "1000 Reasons" anytime the drummer was hitting the snare and bass eight beats, I would do the same thing with my left hand.
3) Pray, pray, pray. This is crucial. Without the Spirit, how can you figure out what the congregation needs? You want to use the piano to lead the congregation's mood into the song. That means stopping once in a while and just playing chords during a quiet session.
4) A local worship leader told me that in Asian music, it's inappropriate for the keyboardist to imitate the singer while she's singing. While this may be true in the world, I've don't always do that, but it taught me to play in harmony or intervals. Play the melody in harmony or intervals like in a hymn book. This is only a suggestion. You want to lead the people, but you don't want to play a solo.
5) As for sounds, this may sound tacky. I didn't use a lavished keyboard. It was janky and basic. (It was a Casio CPR.) So I used string sounds, e-pianos, piano, organ, and a combination of those choices. I used what I was given and I had to compromise with the keyboard.
Have fun and be creative. I always like bringing a pencil to both the rehearsal and performance.
FYI: If you happen to get a guitarist, he'll probably use something called a capo. It's a thing for the guitar to tropose a key to another. So learn transposition. It'll come in handy.
