CHILDREN'S MINISTRY
COMPUTER OR VIDEO PLAYER
Most mobile churches we've come in contact with use some sort of video curriculum for their children's ministry, if this is the case with your church you'll need either a laptop or video player.
PROJECTOR OR TV
Assuming the same you'll also need another viewing screen. Again, because of the high cost of bright projectors and the lowering cost of 4k TVs, we usual recommend TVs as they are currently cheaper and require much less setup time.
CURRICULUM
Lastly you'll need some sort of curriculum to display. We've heard great thing about Orange but it can also be a bit pricy for some. While not as good as Orange, we've also heard that ShareFaith Kids is good for those starting out.