I am glad that you sorted out.
To remove this warning http://prntscr.com/lxdan9 please go to Theme Options and change any option (for example site width to 1180px), save options and then you can change the option back.
Also, please watch our videos – https://www.youtube.com/playlist?list=PLMqMSqDgPNmCCyem_z9l2ZJ1owQUaFCE3
Feel free to ask if you have any other questions.
Regards