Google Workspace Nonprofit basic tier is free for authorised NFP domains.
Product features for each of the Nonprofit Workspace offerings is available here: https://www.google.com/nonprofits/workspace/compare/
Sign up for Google Workspace here: https://www.google.com.au/nonprofits/
Eligibility requirements & how to start the sign up process is available here: https://support.google.com/nonprofits/answer/3367631
Instructional videos about Google for Nonprofits is available here: https://www.youtube.com/@GoogleforNonprofits/videos