Hi BenMatthews7149,
There is no trial version for Project Online plan.
Project Online plan can be purchased either under Office 365 Business plans and Enterprise plans in the following links: http://products.office.com/en-us/business/compare-more-office-365-for-business-plans
If you don’t have any plan above, you can only purchase the Project Online plan under a new tenant in the following link: http://products.office.com/en-US/project/project-online-portfolio-management
If you have Office 365 Business plan or Enterprise plan tenant, but have problems when buying Project Online plan under the tenant, please feel free to post back.
Thanks,
Vivian Wang
