You can hide from search fields, but in submit this mandatory field would have to be removed with custom php.
Also in booking, guest is required. And this will require advanced coding skills to apply.
We can guide you to existing files, but if you don’t have the coding skills you may still need a developer assistance, especially to do the changes in child theme and keep these separate from theme updates.
If you wish to know the existing files to make the changes yourself, please open a ticket in support http://support.wpestate.org/ and technical team will give you the files that keep the code as it is now. Please understand we cannot help make this code changes as it’s a complex job.