1. Have you added acf_form_head() and does your theme contain the required wp_footer() call?
2. There are several methods to do this. The first is that acf_form() lets you specify a list of fields that should be shown instead of showing all of them. The second is that you can use an acf/prepare_field filter https://www.advancedcustomfields.com/resources/acf-prepare_field/. You can check to see if the form is shown on the front end and if it is return false from your filter and the field will not be shown.
