code - what did i do wrong steps

[Shane_h]

Hi so i am trying to learn here - inspected the element and found it was the main product liquid that controlled it so added the code  in bold below to that section 

<div id="ProductInfo-{{ section.id }}"
class="{{ product_info_class }}"
data-product-id="{{ product.id }}"
data-product-min="{{ product.metafields.custom.min_qty }}"
style="margin-top: 0; padding-top: 0;">

it was the section yellow - it never worked and wonder why ? this was the url - https://kitout-fitness.co.uk/products/customizable-mockup-ladies-racerback-cropped-tank-top?variant=... what steps would you of taken to solve and  identify the relevant section that needed changing   thanks shane 

[Shane_h]

TBH 

TBH i think im going in the wrong place as you can see below 2 elements when space is inbetween  elements like this - how do you find out as part of problem solving and solution which one is causing that space thanks