First, to handle managing a group of related services, I recommend using target. You can find the details at How to create a virtual systemd service to stop/start several instances together?.
The benefit of using a target is that you can stop and start all the services as a group or individually.
Second, you have to enable services for them to start at boot. Enabling a unit runs whatever directives you have in the [Install] section of your unit files. You can check if a unit is enabled or not with systemctl status your-unit or simply systemctl is-enabled your-unit.