Responsive design is a popular web design strategy used by some of these site builders. This approach reformats the same webpage content to fit different screens. But in terms of SEO (search engine optimization), the search engines only care about whether a site displays suitably on mobile screen sizes. Both Bing and Google have pages where you can enter your URL to see if your site plays on mobile acceptably.
Maybe just like you, at first we didn't have a darn clue about how to build a website, nevermind write half a line of code if our life depended on it! We wanted to build a website to start a side business, and felt overwhelmed, confused & scared about how to actually do it, which builder to use, and making wrong decisions. After years of trials & errors using different website builders, we're here to share our experiences with you.