Please go to Sections → main-product.liquid and there, you can find for loop starting from line no 71 to 436 as shown in the screenshot. It is for displaying different elements like Price, title, and reviews.
If you want to place free shipping below Price, then you can place the code in the {%- when ‘price’ -%}
Similarly, If you want to place free shipping below title, then you can place the code in the {%- when ‘title’ -%}
Please place below code.
{% if product.tags contains 'free-shipping' %}
{% endif %}
