elastic4sのreadmeには、始めに必要なすべての例があります。確かに、高度なユースケースでは軽いですが、単純な例では十分です。
たとえば、quick start guideを読んでください。
import com.sksamuel.elastic4s.TcpClient
import com.sksamuel.elastic4s.ElasticDsl._
object Test extends App {
// Here we create an instance of the TCP client
val client = TcpClient.transport(ElasticsearchClientUri(host, port))
// await is a helper method to make this operation synchronous instead of async
// You would normally avoid doing this in a real program as it will block your thread
client.execute {
indexInto("bands"/"artists") fields ("name" -> "coldplay") refresh(RefreshPolicy.IMMEDIATE)
}.await
// now we can search for the document we just indexed
val resp = client.execute {
search("bands"/"artists") query "coldplay"
}.await
println(resp)
}