Struggling with CSS for WPForms

Can anyone help me please? I can’t seem to work out how and where to alter CSS for WPForms. http://autolinx.net/testing/contact-us/

I need to add padding to bring it off the edges of the containing box, change the text colour so it is actually readable, and if possible change the submit button colour to #EF3F23

I’ve tried many things I found online but may be attempting to add in the wrong spot.

Any help gratefully accepted!