Template Errors: Trying to update templates and customize templates.

I am trying to update my website colors, design, logos, etc but when I attempt to customize it I get fatal errors. I tried updating the template but I also get an error saying the update failed. See the errors below and let me know if you know what the issue is.

I am currently updated to the most recent version of WordPress (4.8) and I am using WooCommerce with the following templates.

Storefront
Twenty Fourteen
Twenty Fifteen
Twenty Sixteen
Twenty Seventeen

Appearance > Customize
Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 122880 bytes) in /home/goofball/public_html/FanaticPets.com/wp-admin/includes/template.php on line 731

Appearance > Header

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 30720 bytes) in /home/goofball/public_html/FanaticPets.com/wp-admin/includes/template.php on line 1017

Appearance > Background
Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 30720 bytes) in /home/goofball/public_html/FanaticPets.com/wp-admin/includes/template.php on line 1017

And when i go to Themes I can see that it asks for the “Storefront” theme to be updated. But when I attempt to update it I get the following: “Update Failed: Internal Server Error”

If I select the customize button on that template it returns the fatal error below.

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 30720 bytes) in /home/goofball/public_html/FanaticPets.com/wp-admin/includes/template.php on line 1017

Additionally, if I try to add a new template I receive another error.

“An unexpected error occurred. Something may be wrong with WordPress.org or this server’s configuration. If you continue to have problems, please try the support forums.”

As for WooCommerce, In the plugins section it does say there is an update available but when I attempt to update it I see the below error:

“Update Failed: Internal Server Error”