Checkout Max Execution Time Reached on Fresh Install

[timnolte]

Describe the bug
On a fresh install of the plugin if the plugin general settings are not saved then some options have no default set causing the plugin to failed completing the load of the Checkout page.

To Reproduce
Steps to reproduce the behavior:

1. Install plugin
2. Activate plugin
3. Add an item to the cart
4. Proceed to checkout.

Expected behavior
Even if the plugin general settings have not been touched then the Checkout page should still run as normal. After plugin activation an admin notice should be display instructing Administrators that they need to configure the plugin settings with a link to take them to that screen.

Isolating the problem (mark completed items with an [x]):

• I have deactivated other plugins and confirmed this bug occurs when only WooCommerce and this plugin are active.
• This bug happens with a default WordPress theme active, or Storefront.
• I can reproduce this bug consistently using the steps above.

WordPress Environment

• Website URL: http://penguin.linux.test:8889
• PHP Version: 7.3
• WordPress Version: 5.4.1
• WooCommerce Version: 4.1.0
• Plugin Version: 1.3.12
• WordPress Timezone Setting: America/Detroit
• WordPress Date Format Setting: F j, Y
• WordPress Time Format Setting: g:i a
• All Plugin Start/End Pickup Time Settings: 10:00am-7:00pm
• Plugin Pickup Time Interval Setting: 30 Minutes
• Plugin Pickup Time Delay Setting: 1 hour
• Plugin Pickup Time Open Days Ahead Setting: 1 day

[timnolte]

This is no longer occurring.