You launch the indi weatherradio service with the start command as you say.
You can also use a different syntax which gives the same result
sudo systemctl stop indi-weatherradio.service
What you are typing is fine for controlling the service, you can use other methods but you only need one.
You need to get the output of the indiserver into a file to record what is happing in case of a crash.
To do this you need to edit the service script to redirect the output to a file.
First stop the service
Use a text editor to edit the service file /etc/systemd/system/indi-weatherradio.service
Change the exec start command from
ExecStart=/usr/bin/indiserver -v indi_weatherradio
ExecStart=/usr/bin/indiserver -v indi_weatherradio >> /tmp/weatherradio_output.txt