In the schematic below, you can see at one glance the 5 steps required to complete a wpsolr configuration. For Elasticsearch and Apache Solr.

1. Install Elasticsearch or Apache Solr
2. Create and configure your index
3. Select and configure the WPSOLR extensions you need
4. Configure the search as you like it
5. Index all your data

Each of these steps is described with great details in the following documentation.