Hi Matthew and welcome to the forum:
Given that the focus confirmation light is blinking, it suggests that the camera cannot achieve focus. Assuming that the scene has enough contrast and light to allow focusing, it suggests that something may have gone amiss with the lens.
First, I would suggest turning off the camera, removing the lens from the camera body and re-installing it, listening for a distinct click as it locks.
What lens are you using with your camera: please do read the info from the front face of the lens: for example it could say EF-S 18-55 III IS USM, or some such? That can specificity can be significant. If you have access to another lens it would be helpful to switch lens and see if you get the same result. If not, then it further suggests that the lens autofocus is the issue.
If you can come back with those things accomplished it will help us to help you.
cheers, TREVOR
"The Amount of Misery expands to fill the space available"
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
