1: Online store > themes > Actions > Edit code > Sections > product-template.liquid
2: find the class name ‘product-single__title’, if you have not edited code before then its in line 131
demo ( you can edit base on it
{% assign product_title_arr = product.title | split: " - " %}
{% for product_title_item in product_title_arr %}
{% if forloop.index == 1 %}
#
{{ product_title_item }}
{% else %}
{{ product_title_item }}
{% endif %}
{% endfor %}


