You can build links to any pages on your site anytime you like, even if that site is a new site, etc, as there are simply no restrictions or no good/bad in doing so.
Just make sure that the links that you build to - are quality links, that are vetted against various metrics.
You can also build links using automated tool - the key is always screen through the link list against the metrics, and make sure that the sites that you are building links on, have some good metrics, otherwise, building spam links are like firing blanks that consume time and achieves nothing in the end.
But if the links have some link juice (some good metrics) you'll see that these would gradually contribute to your site over time, in terms of authority.