Unable to proved IP Address

I am new to Xfinity and I conected the modem given to me by Xfinity and follow all directions. It shows as a strong signal however it says: Failed to obtain IP Address . HELP!! I do not want to have a tech come out where I will have to pay for (around $70) if it is a simple fix. Hard time right now. Thank you all in advance for your help 🙂