Since copy/paste from codepen you can ignore the first warning and first two errors.
There are HTML coding errors you should be aware of and address.
Codepen provides validators for HTML, CSS and JS. Click on the down arrow in the upper right of each section and then click on the respective ‘Analyze’ link.
The one for CSS is good. Use it, there are things to clean up.
You may have to do it more than once after cleaning up the first warning. They may affect the way your page displays.
The one for HTML misses things which is why I recommend W3C
Make all of your styling external
The required field ‘company name’ should not be validated as if it were an email address.
Maybe make the submit button look like a button instead of a bar.