How long is the free trail of Target Process valid after registration?
A form needs to be filled for this - https://www.apptio.com/products/targetprocess/targetprocess-demo-request/ and then our sales team will get in touch with them for provisioning accounts and demo. They can also mail tp-sales@apptio.com for details.
About the question you asked for Epic creation. we can create Epic without linking toPortfolio epic. Epics can stand alone. You can refer this link to know more about Epic https://www.targetprocess.com/guide/entity-types/epics/