ECS template initial import

I am having trouble figuring out how to start using an ECS index template.

I have read through a lot of the documentation and familiarized myself with the concepts of ECS.
Now I want to test it in practice.

The questions I have are:

  1. Where can I find the latest ECS index template ? Which file(s) do I need to download ?
  2. What is the official (best practice way) for starting with ECS ?
    After importing a json a colleague gave to me I now see the index template in the "Legacy index templates", which means something is not correct in this json.

I want to have all the fields that are described in the ECS field reference.

P.S: I don't want filebeat or logstash to import the index template because I don't need to use them in my current environment since we are using fluentd on the client side.

Elasticsearch, Kibana version: 7.8.1