We had mandatory N to 1 meetings. Those weren't that useful for us (it felt like we were a bit further ahead than other companies) but a few companies got a lot of value out of it.
Our optional 1-1 were insanely useful. Our mentor was a yc alum saas cofounder. He was took notes and saw our homework every week. His perspective was priceless and there weren't many problems we were facing that he hadn't already seen. Like other people mentioned, you come with a problem and they help you understand how to tackle it.
Create systems by which people come to know about your site and want to visit it to solve a problem they have.
For example, SEO content marketing targets problems people search Google for and create content that helps solve that problem while advertising the product/service in some way. A good example of this is Digital Ocean's "how to set up software X on operating system Y" articles - good SEO, solves people's problems, and advertises directly to their customers/users.
There are other implementations, like more traditional display advertising and product reviews, but they all follow the same formula: create awareness and gives people solid reasons to come to your product/site/app.
It was useful for us. What we got out of the 1-1s depended on our effort preparing for it -- how we communicated our value prop, how succinctly we described the problems we're having, etc.
Was that actually useful? I can't imagine them understanding (or remembering) anything about your company in that little time.