Start here.

https://cloud.google.com/spanner/docs/

You may have to download and install special libraries.

https://cloud.google.com/spanner/docs/reference/libraries

This may include the use of Python or other third-party languages.

You may find it’s easiest to use the REST web services to access Spanner.

https://cloud.google.com/spanner/docs/reference/rest

This is a very involved topic, and one we cannot cover in a forum post. You may wish to consider hiring someone with experience in Spanner to assist.