If you're looking for something like that for free... then you need to outreach manually to relevant websites and offer them content for an exchange of a link.
Good luck, a million and a half SEOs are out there doing that all day.
You better come up with a better way to go about it. Offer them an infograph or video, something that will offer TRUE info, not garbage with a link on it.
I'd also say, where is your branding at, because I'd say you're not even at the point where you should even worry about such things if you're pushing for
"free".
You're a beginner if you're asking this question.
Learn to brand yourself.
One of these day maybe I'll create a BHW quick run down of how I do it. I have a course but it's not available for the public and will never be...
Just the way a real boss SEO has to play it sister.
But start with branding yourself across 75-200+ profile sites and fill them out completely. Get your brand name or anchor text in the URL. Make sure
you intertwine your social profiles throughout these.
And you'll have something that most SEOs will never do, thusly you'll be viewed as a real business online instead of a SEO joker.