Building social proof for business

I do a lot of outreach for my businesses. Though because it's cold, there's no trust built at all. Of course, a call is made, but a lot of the time these business owners just google the company name.

Which is good because I want them to see my site, see my reviews from Google, and our case studies. But I really want to fill up the SERPs for my company name.

What's the best way to build social proof for a business?

Maybe a press release campaign? You can check some sellers in the marketplace and ask them if that's going to fill up the SERPs with your company name or not.

You can fill the first page of Google with positive reviews from top review websites, so When someone searches your company name on Google, The Top Pages of Google will show positive reviews from multiple review websites

Press release, citation listing.

I provide google page reviews to clients so that they can have a good social proof for their customers. It is one sure shot way of customers lurking in the market to find products and services to see that the business is actually active with a good customer base.