I am new and I have no idea about SEO.
Hi, I wrote a long reply to a similar question some time ago.
This is the part I wrote about links and link building:
"If your content is good, people may link to your site. Aside from using relevant directories, articles and natural social media links to your site, every other kind of link can be seen as unnatural by Google. It will assess whether the link is natural or not. A small number of links, bought from reputable places (ie, a blogger in your niche who sells a couple of links on their site) is fine. Do you think 1000(0) links appearing for a new site within a month looks natural? Is it possible that those who offer this service on Fiverr are smarter than Google and its staff? Definitely not. It might give a short boost but it will be spotted and penalized."
I will add that just because a seller says their links are “natural”, “safe”, “Google Approved” etc, does not mean that they are.
If you would like to see the full reply which talks a lot more about good and bad SEO then you can check the original post here which has my comment below it.