There are install guides here for development purposes: dev-install
You should not use a developer install to run a community though.
If you do not have access to a credit card you will have a very hard time finding hosting, even for the limited free hosting that exists, credit cards are often used for verification purposes to combat spammers/scammers.
Please search Meta before starting a new topic, this has been asked and answered many times before: Search results for 'free hosting' - Discourse Meta