Hi @dashaluna
The WP WYSIWYG automatically adds in p tags when the value is returned by the get_field function.
This is due to the filters which are run on the WYSIYWG field value which follow the same rules as the standard WP the_content.
To get around the issue, you can load the value without any formatting like so:
the_field('field_name', false, false);
The 3rd false tells ACF to not format the value.
Hope that helps.